Artery Research

Editorial Board

2011-12-01

Blood pressure variability and arterial stiffness

Michel E. Safar — 2011-10-31

Abstract: Blood pressure variability (BPV) is defined by the standard deviation of a given sample of population of normotensive or hypertensive subjects. Recent studies have suggested that this parameter might constitute a cardiovascular risk factor. Reduction of blood pressure variability could be an important purpose of anti-hypertensive treatment, as suggested from experimental studies. In a double-blind controlled investigation, the thiazide compound indapamide was compared to placebo, to the angiotensin blocker candesartan and to the calcium-entry blocker amlodipine for 12 weeks treatment. The 3 drugs reduced significantly and identically blood pressure. Only indapamide and amlodipine reduced significantly BPV. This study was the first to demonstrate the interest of BPV in the setting of a double-blind, placebo controlled, trial.

Regulation of arterial stiffness: Cellular, molecular and neurogenic mechanisms

2011-11-07

Abstract: The lasting legacy of Donald McDonald has been in the establishment of physiological and biophysical principles of the relation of blood pressure and flow in arteries. This relation is determined by physical properties of arteries, among which wall stiffness is a dominant parameter. Increased arterial stiffness leads to an increase in pulse pressure due to alterations in the capacitive properties of large arteries and the increase in pulse wave velocity, which leads to early return of reflected waves. While the haemodynamic and biophysical effects of arterial stiffness have been studied extensively and are well established, the underlying mechanisms responsible for the alteration of the structural properties of the arterial wall are not as well understood. Some potential mechanisms will be addressed in relation to the interaction of the cellular and acellular components and their effect on the structural integrity of the arterial wall. The modification of the smooth muscle cell to influence medial calcification and the endothelium-dependent nitric oxide pathways affecting the extracellular matrix through post-translational modification of proteins form part of positive feedback mechanisms in the regulation of arterial stiffness through cellular and molecular processes. This is further modulated by neurogenic effects on smooth muscle contractility affecting wall stiffness. While the passive effects on the arterial wall due to blood pressure and heart rate cannot be readily modified, uncovering cellular, molecular and neurogenic mechanisms regulating arterial stiffness can offer novel means to interrogate pathways leading to the detrimental effects of degeneration of arterial function and altered relation of pressure and flow.

New insights in ultrasound imaging for cardiovascular diseases and large arteries properties

Mathias Fink — 2011-12-01

Recent developments of ultrafast ultrasound imaging scanners open very exciting possibilities in the field of cardiovascular imaging. Thanks to the new design of the most recent ultrasound scanners that uses a fully software-based ultrasound platform, frame rates as large as 20.000 frames/s are reached today. Compared to classical ultrasound scanners that delivered some 100 frames/s these new possibilities represent a complete breakthrough. We will describe at least three innovations that leverage ultrafast ultrasound imaging. The first one is a new imaging mode that provides quantitative viscoelastic analysis of arterial wall by following the propagation of both pulse waves and shear waves with a spatial resolution and precision that were never obtained with classical techniques. The second one allows to image in a very quantitative way the cardiac elasticity anisotropy by studying shear wave propagation in different directions. The last innovation is new way to perform Doppler flow analysis, from ultrafast scanners, changing completely the performances and workflow paradigms of Color and PW modes. Various results obtained with these techniques in the field of cardiovascular imaging will be presented.

Vascular biomechanics: constitutive modelling and characterisation of the arterial wall

F.N. van de Vosse — 2011-12-01

Insight into the mechanical properties of the arterial wall can give valuable information concerning the understanding of pulse wave propagation in the arterial tree, the genesis and progress of atherosclerosis, vessel wall adaptation and remodelling, and the prediction of the effects of medical intervention, such as blood-pressure regulating drug admission, balloon angioplasty, and bypass surgery. A widely used approach to characterize the mechanical properties of arteries is based on a mixed experimental–numerical method, in which parameters of mathematical constitutive models are fitted to experimental stress–strain data. For wall remodelling studies (Machchyn et al., 2010) these parameters preferably are based on micro-structural information such as collagen content and morphology (Rezakaniha et al.,2011). A generic set of parameters can be obtained from ex-vivo experiments where stress-strain relations can be obtained for transmural pressures ranging from a non-physiological unloaded to physiological fully loaded configuration (van den Broek et al., 2011). If only clinical data at physiological loading are available, extra constraints on the parameter set can be used to obtain a unique characterization (van der Horst et al., 2011). Several aspects regarding the above mentioned micro-structural based models will be discussed during the presentation. For predictive models of pulse wave propagation, micro-structural based constitutive models must be casted into pressure-area relations, whereas, for prediction of adaptation and arterial wall remodeling, the dynamics of smooth muscle cell behavior must be taken into account. Both facets will be shed light upon and illustrated by results recently obtained.

New insight in coronary vulnerable plaque mechanical properties

G. Finet, J. Ohayon, Gilles Rioufol — 2011-12-01

Vulnerable coronary atherosclerotic plaque rupture is a recognized major cause of acute coronary syndrome. Such vulnerable plaques can be detected clinically by various techniques, including intravascular ultrasound (IVUS) and optical coherence tomography. Detecting lesions vulnerable to rupture is a major issue, as it could lead to the development of specific treatment strategies for the prevention of acute thrombotic events. Clinical and biomechanical studies performed recently by our group have originally identified new morphological factors as the key predictors of vulnerability to rupture. Moreover, it is now recognized that prediction of the vulnerable coronary plaque rupture requires not only an accurate quantification of fibrous cap thickness and necrotic core morphology but also a precise knowledge of the mechanical properties of plaque components (IVUS Modulography of Atheroma Plaque). We demonstrated why, in clinical practice, biomechanical plaque instability is not a consequence of Captick alone, but rather of a subtle combination of Capthick, Corethick and Remodindex. Moreover, Residual Stress/Strain (RS/S) present in a vulnerable coronary plaque dramatically influences the spatial stress distribution and spotlights some new sites of stress concentration. RS/S could play a major role in the biomechanical stability of vulnerable coronary plaque and in the growth process of the lipid core. Additionally, we showed that plaque rupture is to be viewed as a consequence not of external pressure alone but rather of a subtle combination of external loading and intraplaque RS/S.

MRI in carotid plaque

C. Oppenheim, E. Touzé — 2011-12-01

The emergence of high-resolution imaging methods has enabled MRI to noninvasively image the fine internal structure of cervical arterial walls. This presentation will provide a comprehensive guide to perform high resolution MRI (HR-MRI) of cervical arteries, including the choice of coils, sequences, imaging parameters, and tips for optimal image quality. HR-MRI of carotid atherosclerosis has the potential to be used in treatment decisions or to monitor the effects treatment options. We will explain and illustrate how to quantify plaque volume, determine atherosclerotic plaque burden, detect plaque composition, and ultimately identify unstable plaque before it leads to a clinical event using HR-MRI. Finally, the role of HR-MRI in the diagnosis of cervical dissection and inflammatory disease of the arterial wall will be emphasized.

What is the future for research in arterial stiffness and central blood pressure ?

Michel E. Safar — 2011-12-01

Please see Invited Speaker Extended Review Papers section.

Molecular mechanisms of the vascular repsonses to haemodynamic forces

S. Lehoux — 2011-12-01

Numerous studies in man and in animals support the relation between low or turbulent shear stress and atherosclerotic plaque location. However, little is known regarding the role of shear stress on the progression and composition of pre-established plaques. A recent prospective study in patients revealed that atherosclerosis regression is a realistic goal in patients, and it can be achieved through increased shear stress. We have used a model of arteriovenous fistula (AVF) developed in the lab, connecting the right common carotid artery with the jugular vein, to increase blood flow over established plaques in the brachiocephalic artery of LDL receptor knockout mice. Animals are placed on a high-fat diet for 12 weeks (wk0-wk12), then divided in three groups : control, sham, or AVF. Sham and AVF animals are maintained on high-fat for 4 weeks post-surgery. Atherosclerotic plaque size in the brachiocephalic artery averages 100,100±13,900μm2 at wk12 (control animals) and progresses to 134,200±15,100μm2 in sham by wk16, whereas it actually regresses by 53% in AVF in the same timeline (63,500±15,100μm2; p<0.02). Relative smooth muscle cell, macrophage, and collagen content are equivalent between groups, but matrix metalloproteinase (MMP) activity is enhanced in the AVF mice, suggesting that these enzymes might participate in the remodeling process. Indeed, in mice treated with MMP inhibitors and TIMP plasmids, MMP expression and activity diminish, and AVF fails to reduce plaque size. Hence, a favorable local shear stress may reverse the atherosclerotic process through a process involving metalloproteinases.

Vascular Remodelling of the Retinal Microcirculation in Hypertension and Diabetes

Roland E. Schmieder — 2011-12-01

In addition to the classical signs of hypertensive nephropathy (e.g. arterial narrowing, arterial venous nicking, retinal haemorrhages or microaneurysms) new technologies have emerged to characterize hypertensive retinopathy more precisely: Scanning Laser Doppler Flowmetry (SLDF) which allows the precise characterization of the remodelling processes in retinal arterioles, and techniques analyzing the retinal microvascular architecture. For example, in patients with essential hypertension and malignant hypertension the length to diameter ratio (indicating generalized narrowing) has been found to be increased and the number of terminal branches (a parameter of capillary density) reduced.

Regulation of arterial stiffness: cellular, molecular and neurogenic mechanisms

Alberto Avolio — 2011-12-01

Please see Invited Speaker Extended Review Papers section.

Advances in arterial stiffness assessment

Evelien Hermeling, Robert S. Reneman, Arnold P.G. Hoeks, Koen D. Reesink — 2011-11-07

Abstract: Although the clinical relevance of arterial stiffness is increasingly recognized, the applicability of arterial stiffness for individual cardiovascular risk assessment is hampered due to technical and physiological difficulties. Arterial stiffness is not constant with blood pressure and not constant over the arterial tree. Currently, stiffness is commonly assessed in individuals over a long trajectory and neglects the pressure dependency. To circumvent these problems, we developed a technique to measure pulse wave velocity (PWV) locally using multiple M-line ultrasound. In the common carotid artery, PWV can only be measured using the dicrotic notch of the distension waveform as fiducial time-point, because the systolic foot is subjected to reflective interference. Dicrotic notch PWV provides a measure of stiffness at near systolic pressure level, which is intrinsically different from systolic foot PWV measured at diastolic pressure. To investigate the effect of pressure on local stiffness, we quantified carotid distensibility coefficients for the diastolic and systolic pressure ranges separately. We found that the diastolic-systolic difference in carotid distensibility varies significantly between individuals and is an independent determinant of left ventricular mass index. Moreover, this pressure dependency appears to increase with age (like arterial diameter), suggesting that this property could be used as a marker for structural remodeling of the artery wall. Biomechanically, the pressure dependency of stiffness directly affects pressure and flow waveform characteristics and their phase relation. Ignoring this may lead to overestimation of the impact of wave reflections on central blood pressure. Our work shows that pressure dependency of arterial stiffness can and should be accounted for to evaluate its implication for pressure augmentation and wave separation analysis.

Advances in Arterial Stiffness Assessment

Evelien Hermeling — 2011-12-01

Please see Career Development Extended Review Paper section.

Large artery remodelling and stiffening in moderate chronic kidney disease

Marie Briet — 2011-12-01

Chronic kidney disease (CKD) is characterized by a very high cardiovascular risk even at moderate stage. Patients with CKD are exposed to traditional cardiovascular factors and to uremia-associated CV factors such as inflammation, oxidative stress, anemia, mineral metabolism disturbance which could affect the structure of large and small arteries. In moderate CKD, large artery damage is mainly characterized by an increase in aortic and carotid stiffness compared to hypertensive and healthy subjects. Interestingly, we recently demonstrated that aortic stiffness did not increase during CKD progression and was not associated with CKD progression. On the contrary, aortic stiffness has a clear impact on the cardiovascular prognostic in end stage renal disease. A maladaptive remodeling of large arteries is the second main abnormality in moderate CKD and is characterized by dilation and a thinning of the arterial wall leading to an increase in circumferential wall stress. The longitudinal measurements of carotid remodeling parameters have shown that intima-media thickness decreased with a slope comparable to the one measured in high cardiovascular risk patients but in an opposite way. We recently demonstrated that, in opposition to aortic stiffness, circumferential wall stress measured at the level of the carotid artery was associated with CKD progression and end stage renal disease.

Inflammation and large arteries

Kaisa Maki-Petaja — 2011-12-01

Firstly, we demonstrated that RA is associated with increased aortic stiffness compared with healthy controls, and that aortic stiffness correlates with current, but not historical measures of inflammation. We also established that patients with RA have reduced endothelial function compared with matched control subjects and that endothelial function is independently associated with inflammatory markers.

Prognostic value of combined assessment of aortic stiffness and calcification in dialysis patients: Outcome data of the calcification outcome in renal disease (cord) study

2011-12-01

Radiographic calcification and arterial stiffness each individually have been shown to predict outcome in dialysis patients. However, it remains unknown whether combined assessment of these markers of cardiovascular (CV) damage also provides additional predictive value.

Differential impacts of hypertension and type 2 diabetes mellitus on arterial disease and cardiovascular outcomes: The strong heart study

M. Roman, B. Howard, J. Kizer, E. Lee, L. Best, R. Devereux — 2011-12-01

Background: Both hypertension and diabetes mellitus (DM) increase risk for subclinical and clinical cardiovascular disease (CVD). The relative extents to which hypertension and DM induce subclinical CVD have not been examined, but recent Framingham data suggest that clinical CVD risk in DM is largely attributable to coexistent hypertension.

Prognostic value of carotid-femoral pulse wave velocity for cardiovascular events: An IPD meta-analysis of prospective observational data from 14 studies including 16,358 subjects

2011-12-01

We have undertaken an individual participant data (IPD) meta-analysis of carotid-femoral pulse wave velocity (cf-PWV) with all cause mortality, CHD, stroke and combined CVD events using data from 14 studies (2 unpublished). Unlike a previous report, which only used published data, we were able to undertake standardised analyses with and without adjustment for cardiovascular risk factors and test, a priori, for potential interactions between cf-PWV and age group, gender, diabetic or hypertensive status on the various outcomes. We calculated discrimination statistics for models with and without cf-PWV, specifically focussing on individuals at intermediate (25-75th percentile) risk of CVD after adjustment for conventional Framingham risk factors. Fourteen studies provided data on 16,358 subjects with 1700 combined CVD events. We derived within study z-scores of log transformed cf-PWV (pooled SD = 3.3m/s). Risk of all outcomes was associated with increased cf-PWV (Table 1) and was linear across the range of cf-PWV values with no evidence of interaction except for age group (see Figure, p-value for trend = 0.0095). The additional benefit of measuring cf-PWV to reclassify intermediate risk individuals was assessed using the net reclassification index. 18.6% (p<0.001) and 22.4% (p<0.001) were appropriately reclassified into higher or lower quartiles of risk for CHD and stroke outcomes respectively. These findings highlight the added value of cf-PWV as an independent predictor, over and above existing risk factors, in intermediate risk groups and for younger subjects. Assessment of PWV should better identify high risk populations that may benefit from more aggressive risk factor management.

Pulse wave velocity and incident heart failure in chronic kidney disease

2011-12-01

Heart failure (HF) complicates chronic kidney disease (CKD) despite improving medical therapy for co-morbidities like hypertension. We hypothesized that vascular stiffness, (aortic pulse wave velocity [PWV]), predicts incident HF in well controlled CKD participants free of HF at enrollment.

Aortic stiffness is independently associated with fatal and non-fatal cardiovascular events in chronic kidney disease stage 2-5

2011-12-01

Objective: Chronic kidney disease (CKD) is characterized by a high cardiovascular risk. Subclinical damage to large arteries has been largely described in CKD and is mostly characterized by an increase in arterial stiffness and an outward remodeling of the carotid artery. However, the predictive value of arterial remodeling and stiffening for cardiovascular events and mortality is still debated in pre-dialysed CKD (stage 2-5).

Arterial stiffness is an independent determinant of compensatory hyperfiltration after kidney donation

P. Fesler, J. Ribstein, G. du Cailar, G. Mourad, A. Mimran — 2011-12-01

After kidney donation, the remaining kidney tends to hyperfiltrate thus limiting the initial loss of renal function. However, the potential determinants of this compensative hyperfiltration (CHF) and the possible influence of arterial function are not known.

Pre-pregnancy cardiovascular risk in women with previous preeclampsia (PET)/intrauterine growth restriction (IUGR)

A.A. Mahendru, C.C. Lees, T.R. Everett, C.M. McEniery, I.B. Wilkinson — 2011-12-01

Women with history of preeclampsia (PET) and delivery of intrauterine growth restriction (IUGR) babies are at increased risk of cardiovascular events later in life. This could be related to endothelial dysfunction, altered arterial stiffness or metabolic abnormalities resulting from pregnancy complications. Alternatively, pre-existing abnormalities in the cardiovascular system may predispose them to both pregnancy related complications and cardiovascular disease later in life. We compared pre-pregnancy arterial stiffness and central haemodynamics between women with previous PET/IUGR and those with previous uncomplicated pregnancies.

Spectral analysis of carotid distension rate and R–R interval (spontaneous baroreflex activity) predicts coronary heart disease risk in patients with moderate chronic kidney disease and in those with normal renal function: the EPP3 study

2011-12-01

The classic technique to evaluate the spontaneous baroreflex is the spectral analysis of finger blood pressure and heart rate. However, baroreceptors respond to deformation and not to pressure per se and the results obtained with this technique can be influenced by the vascular component of the baroreflex. Recently, the spectral analysis of carotid distension rate has been used to study the neural baroreflex. The aim of this study is to test this new technique to predict the coronary heart disease (CHD) risk in patients with moderate chronic kidney disease (CKD) and in those with normal renal function.

Normal and reference values for carotid intima-media thickness

L. Engelen, P. Boutouyrie, I. Ferreira, C. Stehouwer, S. Laurent — 2011-12-01

Increased carotid artery intima-media thickness (IMT) has been widely used as a surrogate marker of atherosclerosis and has been shown to predict cardiovascular disease (CVD). However, the interpretation of IMT values, as measured across different age, sex and risk groups, has been hampered by the absence of normal and reference values comparators. The aim of the present study is therefore to establish normal and reference values for IMT based on a wide population.

Establishing reference values for central blood pressure in a general healthy population and established disease groups

A. Herbert, Reference Values for Arterial Stiffness Collaboration — 2011-12-01

Background and Objective: Estimated central blood pressure is a non-invasive outcome regarded as a prognostic marker of cardiovascular disease. Reference values have been calculated previously in specific populations, for example, in 5,648 healthy subjects from East Anglia and Cardiff in the ACCT study (Hypertension 2008;51;1476-1482). These values are useful not only for assessing flow properties, but for study design in investigating treatments or adverse events longitudinally. This study aimed to establish reference values for a worldwide general population, increasing the flexibility of their use.

Differential effects of BNP and no donors on human forearm muscular conduit arteries

H. Fok, B. Jiang, A. Donald, P. Chowienczyk — 2011-12-01

Nitroglycerin (NTG) selectively vasodilates muscular conduit arteries. Whether other nitric oxide (NO) donors and natriuretic peptides have similar effects is unknown. The aim of this study was to compare effects of NTG, sodium nitroprusside (NP) and brain natriuretic peptide (BNP) on the radial artery (a muscular conduit artery) and forearm resistance vasculature. Phentolamine (PHT), a vasodilator with minimal vasodilator effects on conduit arteries was used as a control. Healthy normotensive men aged 19-45 years were studied. The right brachial artery was cannulated using a 27 gauge needle and an intra-arterial infusion of each vasodilator (PHT, 10, 30 and 100μg/min, n = 9; NTG 0.03, 0.1, 0.3, 1.0, 3.0 μg/min, n = 8. NP, 0.3, 1, 3 μg/min,n = 11; BNP 0.03, 0.1, 0.3, 1, 3 μg/min n = 8) given on separate occasions or after washout. Forearm blood flow (FBF) was measured by venous occlusion plethysmography and change in radial artery diameter by ultrasound. The percentage change in diameter for different drugs was compared at doses producing the same change in FBF (DFBF). The efficacy of dilation of the radial artery was NTG>NP >BNP>PHT. Radial artery dilation by NTG and NP but not BNP was greater than that by PHT (P <0.05) and radial dilation by NTG greater than that by BNP (P<0.05). These results demonstrate that drugs acting on the guanylyl cyclase – cGMP pathway have differential actions on muscular conduit arteries.

The “marathon paradox”: Decreased intima-media thickness and improved flow-mediated dilatation, but increased aortic stiffness

2011-12-01

Background: Arterial stiffness, wave reflections, endothelial dysfunction and carotid intima-media thickness (cIMT) are predictors of cardiovascular events. Marathon running is an extremely vigorous aerobic exercise.

Common carotid artery properties are related to sympathetic outflow and cardiovascular variability

2011-12-01

Objective: The relationship between sympathetic activity and common carotid artery (CCA) properties is unknown. We therefore tested the hypothesis that mechanical properties of arterial wall are independently linked to muscle sympathetic nerve activity (MSNA) and cardiovascular variability.

Arterial stiffness is a major independent determinant of visit-to-visit variability in SBP: A 9.1 year follow-up in treated hypertensives

V. Nguyen, C. Collin, J. Varinot, P. Boutouyrie, S. Laurent — 2011-12-01

Objective and background: Aortic stiffening, which favours the wave propagation generated by changes in cardiac output, and exaggerates the early return of wave reflection generated by changes in vasomotor tone, can increase the variability in SBP.

Distance measurement for pulse wave velocity calculation – Comparison with invasive findings

2011-12-01

Background: A more simple yet accurate method for assessing travel distance (TD) for calculation of carotid-femoral pulse wave velocity (cfPWV) is desirable to improve acceptance of the method in clinical routine.

Lifetime adherence to a Mediterranean diet (MD) pattern is associated with lower carotid stiffness in young adults: The Amsterdam growth and health longitudinal study

2011-12-01

Purpose: To investigate whether lifetime adherence to an MD pattern (i.e., from adolescence to adulthood) is associated with arterial stiffness in adults. Methods: Longitudinal data on dietary intake (2-8 repeated measures; ages 13-36) were retrieved for 373 subjects in whom carotid stiffness was assessed by means of ultrasonography at age 36. An MDscore [range: 0 to 9 (higher values indicate better adherence)] was calculated based on values < or > the sex-specific medians or pre-defined cut-off values of vegetables, legumes, fruits/nuts, whole grains, fish, meat/poultry, dairy products, alcohol and the ratio of mono-unsaturated to saturated lipids intake. Adherence to an MD pattern (yes/no) was defined based on values > or < median of the MDscore. We used generalized estimating equations to compare, throughout the 24-yr longitudinal period, the MDscore between subjects with increasing levels [i.e., tertiles (T)] of the inversed distensiblity (DC-1) and compliance coefficients, and Young's elastic modulus.

Impact of urban versus rural environment on central blood pressure, aortic stiffness and wave reflections: The PURSE-HIS study

S. Thanikachalam, V. Harivanzan, S. Ramasamy, C.M. McEniery — 2011-12-01

Urbanisation of developing countries has had a marked impact on population health. In particular, in India, the prevalence of coronary heart disease is markedly increased in urban versus rural settings. The aim of the current study was to assess the impact of geographic location on large artery stiffness and central blood pressure (BP) as part of the PURSE-HIS study.

Independent relation between ethnicity, baseline haemostatic variables, arterial stiffness and mortality: A 22-year follow-up study

S.G. Anderson, A.H. Heald, J.K. Cruickshank — 2011-12-01

Objectives: To examine the relationship between haemostatic factors, pulse wave velocity (PWV), blood pressure (BP) and mortality in British Europeans, African-Caribbeans (AfC) and Gujarati Indians.

Unsupervised non-invasive measurement of aortic pulse transit time by means of electrical impedance tomography

J. Solà, A. Adler, A. Santos, G. Tusman, F. Suárez Sipmann, S.H. Bohm — 2011-12-01

Objectives: This study provides first experimental evidence on the feasibility of measuring Pulse Transit Time (PTT) values within the aorta by means of non-invasive and non-obtrusive Electrical Impedance Tomography (EIT) technology.

Predicting the functional impact of residual aortic coarctation lesions during exercise using advanced computer model simulations

2011-12-01

Background: Exercise can be used to unmask the functional impact of a residual narrowing and/or stiffening following treatment of aortic coarctation. Measurements of the hemodynamic response during exercise are, however, difficult to perform and not very accurate, as suspension of exercise during imaging can be required or a low temporal resolution might be insufficient at the high heart rates present during exercise. This work aims to predict central aortic hemodynamics during exercise using advanced modeling tools.

Oxidative stress and inflammation: Implication in endothelial dysfunction and cardiovascular aging on murine models

2011-12-01

The aim of the study was to characterize cardiovascular aging with functional (Doppler) and molecular (RT-qPCR and immunohistochemistry quantifications) approaches using three murine models. Molecular studies on aorta (AO) and mesenteric arteries (MA) were used to explore the role of oxidative stress and inflammation. Time-induced aging model corresponded to 25 months-old C57Bl/6J mice feed with standard diet. Doppler exhibited a concentric left ventricle hypertrophy with a decreased aortic distensibility, and an increased aortic thickening. This model presented both a decreased Thioredoxin1 expression (AO and MA) and an increased NADPH oxidase (MA) expression. Inflammation markers were increased in MA (IL-1beta in MA and in AO (IL-6, TNF-alpha). Three months with High Fat and Protein Diet (HFPD) at 9 months induce a major hyperlipidemia. This model exhibited a dilated cardiopathy with both a decreased aortic distensibility and an increased aortic thickening. HFPD increased NADPH oxidase, IL1-beta and TNF-alpha expressions and decreased Thioredoxin1 expression (AO and MA). The mixed model corresponded to 25-months old C57Bl/6J mice feed for 3 months with HFPD. They presented a major cardiopathy with a decreased aortic distensibility, and exhibited both a major oxidative stress (increased NADPH oxidase and decreased Thioredoxin1 in AO and MA) and a major endothelial inflammation (increased IL-1beta, IL-6 and TNF-alpha in AO and MA). eNOS gene was not modify in any model. We conclude that NADPH oxidase and Thioredoxin1 seem to play a key role in the arterial aging process and might be interesting potential targets for therapeutics assays.

Cardiotrophin-1 induces structural and mechanical changes in aorta

2011-12-01

Aims: Cardiotrophin-1 (CT-1), a cytokine belonging to the interleukin-6 family, exerts proliferative and secretory effects in vascular smooth muscle cells. We investigated the morphological, micromechanical and molecular vascular changes induced by chronic CT-1 administration in rats.

Acute β-adrenergic blockade increases aortic wave reflection in young men and women: Differing mechanisms between sexes

D.P. Casey, T.B. Curry, M.J. Joyner, N. Charkoudian, J.N. Barnes, E.C. Hart — 2011-12-01

Acute β-adrenergic blockade increases aortic wave reflection, however, the mechanisms remain unclear. Evidence suggests that β-adrenergic receptor sensitivity in the peripheral vasculature differs between sexes. Therefore, the goal of this study was to examine whether β-adrenergic blockade alters aortic wave reflection and forearm vasoconstrictor responsiveness to a similar extent in young men and women. In thirty-one subjects (16M/15F; 26±1 years) non-invasive aortic pressure waveforms were synthesized from high-fidelity radial pressure waveforms via applanation tonometry before and during systemic β-blockade (0.25 mg/kg bolus, followed by 0.004 mg/kg/min continuous infusion of propranolol). Forearm vasoconstrictor responses to exogenous intra-arterial norepinephrine (NE) were also assessed in a subset of subjects (13M/9F). Wave reflection characteristics are summarized in . β-blockade increased aortic augmentation index (AIx) and wave reflection amplitude (aortic augmented pressure (AG)) in both sexes. However, the increase in wave reflection tended to be greater (P<0.05 and P=0.07 for AG and AIx, respectively) in women following β-blockade. AIx adjusted for HR (AIx@75bpm) increased in women following β-blockade, whereas it was unchanged in men. Moreover, the change (Δ) in AIx was inversely associated to ΔHR only in men (r=-0.54, P<0.05). Finally, β-blockade caused an enhanced forearm vasoconstrictor response to exogenous NE in women (Figure 2). Our data suggest that: 1) aortic wave reflection is increased to a greater extent in women following systemic β-blockade; and 2) the mechanism for enhanced aortic wave reflection appears to be mediated by a reduced HR in men, whereas less peripheral β-mediated vasodilation likely contributes in women.

Relation between blood flow and arteriolar morphology and reduced vasodilatory capacity in hypertenisive patients with increased arteriolar wall-to-lumen ratio in the human retinal circulation in vivo

M. Ritt, J.M. Harazny, C.H. Ott, U. Raff, G. Michelson, R.E. Schmieder — 2011-12-01

Objective: We hypothesized that blood flow and arteriolar morphological changes are related to each other in the human retinal vascular bed. Methods: The study cohort comprised 141 non-diabetic untreated male patients with or without arterial hypertension but without evidence for cardiovascular disease. Retinal capillary blood flow (RCF) before and after exposure to flicker light and to infusion of nitric oxide (NO) synthase inhibitor N-monomethyl-L-arginine (L-NMMA), and parameters of retinal arteriolar morphology, e.g. wall-to-lumen ratio, were assessed non-invasively and in vivo by scanning laser Doppler flowmetry.

Impact of 3D culture of mesenchymal stem cells to repair expanding AAAS

F. Mohand-Kaci, N. Assoul, R. Bosc, E. Allaire, M. Zidi — 2011-12-01

Abdominal aortic aneurysms (AAAs) are characterized by extracellular matrix degradation and mesenchymal cells rarefaction. In this context, the use of mesenchymal stem cells (MSCs) opens the way for the cell therapy to repair the damaged arterial wall. This study proposes to investigate a cellular therapy by using a 3D structure of MSCs encapsulated in a hyaluronic acid (HA) hydrogel. We show that the morphological remodeling is induced when the MSC is seeded in the hydrogel. The expression marker is not modified and the cell plasticity is better preserved in 3D culture in comparison with the 2D case. The comparison also shows that the ratio of apoptosis cell is reduced when physiological environment is mimicked by applying dynamical strain. Based on these results, the Xenograft model of AAA on the rat [1] is used to test the capability of the MSC to repair the aneurysm. Thus, after 7 days, the endovascular injection in rats tends to stabilize the diameter of AAAs. In summary, preliminary results indicate that (i) the proposed 3D HA hydrogel preserves most of MSC properties, (ii) the 3D culture may allow understanding better MSC stabilizing properties in AAAs, (iii) the investigation of the stresses in the artery wall would be necessary [2].

In which extent gamma-glutamyltransferase contributes to the vasorelaxant effect of s-nitrosoglutathione?

2011-12-01

S-nitrosoglutathione (GSNO) exhibits higher stability than nitric oxide (•NO) and plays an important role in vasoreactivity as it serves as •NO storage and transport, and is a source for protein nitrosation. As gamma-glutamyltransferase (GGT) is involved in •NO release from GSNO, we investigated whether GGT influences the vasorelaxant effect of GSNO in the rat aorta.

Microcirculation abnormalities as related to arterial stiffness and central blood pressure in hypertensive patients

2011-12-01

Background: The possible relationships between indicators of small resistance artery structure and of large artery distensibility have not yet been evaluated. Aim: to assess the relationship between carotido-femoral pulse wave velocity (CF-PWV), central blood pressure (cBP) and vascular alterations in small resistance arteries (media to lumen ratio, M:L) in patients with primary and secondary hypertension Patients and methods: In 65 patients (mean age 53±14 years, 31 F, 21 with diabetes mellitus type 2, 14 never treated) with essential (n= 32) and secondary (n=33) hypertension, pulse wave velocity was measured (Complior)and PW analysis was performed (Sphygmocor). In all patients small-resistance arteries were dissected from subcutaneous fat biopsies and mounted on an isometric myograph, for the measurement of the M:L. Results: Mean values of PWV and of M:L ratio were 11.4±2.6 m/s and 0.09±0.019, respectively. M:L ratio was significantly related to brachial systolic blood pressure (SBP) and pulse pressure (PP) (r=0.40 and 0.39, p<0.001, respectively) and to central SBP and PP (r=0.44 and 0.46, p<0.001, respectively). A positive correlation was observed between M:L and PWV (r=0.43, p< 0.001); this correlation remained statistically significant after adjustment for age and SBP (beta= 0.29, p=0.03). M:L ratio was also associated to augmentation pressure (r=0.42, p< 0.001); again this correlations remained statistically significant after adjustment for age, gender, mean BP and also for CF PWV. Conclusions: In hypertensive patients the presence of structural alterations of small resistance arteries may be associated with the increase in large arteries stiffness and, possibly contribute to an increase in central pressure by earlier wave reflections.

The information contained in wave reflection

N. Westerhof, B.E. Westerhof — 2011-12-01

Wave reflection associates with cardiovascular events. However, it is less clear what information on arterial function, such as arterial stiffness and vascular resistance, can be derived. We therefore set out to find the relations between parameters obtained from wave shape analysis (Augmentation Index, Inflection and Shoulder points) and from wave separation analysis (Reflection Magnitude, and arrival time of the reflected wave) and aortic stiffness and taper.

Using finite element analysis to model acoustic radiation force imaging (ARFI) of carotid artery plaques

J.R. Doherty, D.M. Dumont, M.L. Palmeri, G.E. Trahey — 2011-12-01

The sudden rupture of carotid artery plaques can trigger an ischemic stroke event and eventually lead to death. Unfortunately, the identification of unstable plaques continues to elude clinicians. The use of Acoustic Radiation Force (ARF) to non-invasively provide a relative measure of tissue stiffness has shown promise for differentiating softer, lipid filled plaque regions believed to be more vulnerable than stiffer, calcified plaque regions1.

Tissue factor pathway inhibitor: A new link between arterial stiffness, pulse pressure and coagulation in postmenopausal women

V. Regnault, A. Kearney-Schwartz, H. Louis, B. Pannier, A. Benetos, P. Lacolley — 2011-12-01

Objective: To investigate in women over 60 whether aortic stiffness and/or pulse pressure (PP) are associated with selected procoagulant and/or anticoagulant factors, and to examine whether pulsatile stretch influences these factors in human vascular smooth muscle cells (VSMCs) in vitro.

Which one is more important in prognosis between carotid intima-media thickness and carotid plaque?

T.G. Kwon, K.H. Kim, W.H. Kim, D.J. Yang, J.H. Bae — 2011-12-01

Background and Objectives: Carotid intima-media thickness (CIMT) and plaque are both important in primary prevention. However, it is still unclear which one is more important in prognosis in patients with coronary artery disease (CAD).

Aortic stiffness measurement improves the prediction of asymptomatic coronary artery disease in stroke/TIA patients

D. Calvet, E. Touzé, S. Laurent, J.L. Sablayrolles, P. Boutouyrie, J.L. Mas — 2011-12-01

Background: Aortic stiffness is an independent predictor of coronary events. We assessed the predictive value of aortic stiffness for ≥50% asymptomatic coronary artery disease (CAD) in a stroke population.

Systolic time intervals derived from carotid artery distension waveforms for integrated cardiovascular risk assessment

K. Reesink, P. Boutouyrie, P. Brands — 2011-12-01

Background: Circulatory biomechanics dictate that, with given arterial compliance and pulse pressure, left ventricular ejection and isovolumic-contraction durations (Tej and Tic) reflect systolic ventricular function. Cardiovascular risk assessment, therefore, may benefit from accessible and reproducible measurement of these systolic time intervals (STI). We recently developed a tool to extract STI from carotid artery distension waveforms. We used it here to investigate whether systolic ventricular function is different in patients requiring chronic beta-blockade (BB) compared to controls.

Effect of aging on the annual changes of central hemodynamic indices in middle-aged men: A prospective evaluation

H. Tomiyama, A. Yamashina — 2011-12-01

Objective: To examine the effects of aging on the annual changes of the pressure wave reflection (PWR) and central blood pressures (CBPs), prospectively. Background: Such prospective study has not been conducted.

Blood pressure variability in relation to autonomic nervous system dysregulation: The X-CELLENT study

Y. Zhang, D. Agnoletti, J. Blacher, M.E. Safar — 2011-12-01

To investigate the association of autonomic nervous system dysregulation with blood pressure variability. Of 2370 participants in the X-CELLENT study, 577 patients (59.0±10.2 years) were randomly selected to participate in an ambulatory blood pressure monitoring ancillary study. We proposed a novel autonomic nervous system regulation index termed dSBP/dHR, which was defined as the steepness of the slope of the relationship between 24h systolic blood pressure and heart rate for each participant. Within-subject standard deviation of systolic blood pressure, weighted for the time interval between consecutive validated readings from 24h ambulatory blood pressure monitoring, was used to evaluate blood pressure variability. When dSBP/dHR was divided into tertiles, from tertile 1 to tertile 3, we observed a progressive increase in daytime systolic blood pressure, a progressive decrease in nighttime systolic blood pressure, and consequently a progressive increase in day-night systolic blood pressure gradient (P<0.001). On the contrary, standard deviation of both daytime and nighttime systolic blood pressure were consistently and significantly increased from tertile 1 to tertile 3 (P<0.01). Both before and after adjustment for age, gender and 24h mean blood pressure, all of these increasing or decreasing trends reached statistical significance (P<0.01). Furthermore, in our sensitivity analysis, when men and women were considered separately, the present finding remained unaltered. In summary, autonomic nervous system dysfunction was associated with the enlarged day-night systolic blood pressure gradient and more variable systolic blood pressure in 24 hours in patients with essential hypertension.

Carotid function and baroreceptor sensitivity in moderate chronic kidney disease: The EPP3 study

2011-12-01

Introduction: Short-term variation of blood pressure (BP) is largely controlled by autonomic function though the baroreflex. Carotid distension rate was recently introduced instead of BP to evaluate the carotid function and neural component of the baroreflex in small populations. Autonomic dysfunction and arterial stiffness occurs in patients with severe chronic kidney disease (CKD) but little is known in moderate CKD.

The role of pulse pressure for cognitive decline in hypertension

T. Yaneva, R. Tarnovska, L. Traykov — 2011-12-01

Objective: Pulse pressure (PP), as a marker of large artery stiffness, is a risk factor for target organ damage in hypertension (HT). We hypothesized that elevated PP, as a marker of enhanced arterial stiffness, may be correlated with specific early target organ damage (TOD) of the brain - mild cognitive impairment (MCI).

Relation of central and brachial blood pressure to ECG left ventricular hypertrophy. The Czech post-MONICA study

P. Wohlfahrt, D. Wichterle, J. Seidlerova, J. Filipovsky, R. Cifkova — 2011-12-01

Objective: Central blood pressure (BP) has been shown to be a better predictor of target organ damage and cardiovascular events than brachial BP. Whether central BP is a better predictor of left ventricular hypertrophy (LVH) determined by electrocardiography is not known.

Prevalence of resistant hypertension in a general population in northern Italy: Associated cardiovascular risk factors and target organ damage

2011-12-01

Background: Resistant hypertension (RH) is defined by most guidelines as blood pressure that remains above goal despite use of at least 3 antihypertensive agents of different classes, including a diuretic, prescribed at optimal doses. Few data are available on the clinical characteristics and on the prevalence of different forms of organ damage in these patients. Aim of the study was to evaluate the prevalence of RH and the presence of associated cardiovascular (CV) risk factors and target organ damage (TOD) in a group of hypertensive patients selected from a general population sample in Northern Italy (Vobarno Study). Methods: 478 subjects (mean age 58±3 yrs, 44% males, 66% hypertensives) underwent laboratory examinations and both clinic and 24 hours BP measurement (Spacelabs 90207). Left ventricular (LV) and carotid artery structure were assessed by ultrasound and carotid-femoral PWV was measured using Complior SP (Artech, Pantin, France). Results: among treated hypertensive patients 9.5% were defined as resistant. Patients with RH were older (mean age 69±4 vs 60±9 yrs, p<0.01), had higher glucose values (115±47 vs 103±24 mg/dl, p<0.05) and were more often of female gender (female 73% vs male 27%, p<0.05); no difference in BMI and lipid levels was observed. Estimated glomerular filtration rate (MDRD) was lower in RH (72±17 mL/min/1,73 m2 vs 82±16, p<0.01). Patients with RH had greater LV mass index (47.7±10.5 vs 40.7±10.0 gr/m2.7, p <0.001), LV relative wall thickness (0.42±0.08 vs 0.38±0.05 p <0.001), intima media thickness (Meanmax 1.47±0.42 vs 1.18±0.30 mm, p =0.01) and PWV (13.3±2.8 vs 11.8±2.8 m/sec, p<0.05). Conclusions: in a group of hypertensive patients selected from a general population in Northern Italy the prevalence of RH was relatively high. Patients with RH were older, had higher glucose values and a higher prevalence of cardiac, vascular and renal organ damage.

Increased age, body mass index and low HDL-C levels relate to an echolucent structure of the carotid intima–media thickness: The METEOR study

2011-12-01

Introduction: Echolucent plaques have high lipid contents and are related to a higher cardiovascular risk. Studies relating echolucency to cardiovascular risk in early stages of atherosclerosis are limited. We studied the relation between cardiovascular risk factors and the echolucency of the carotid intima–media thickness (CIMT) in low-risk individuals.

B-proof: Is arterial stiffening associated with homocysteine?

S.C. van Dijk, A.H. van den Meiracker, F.U.S. Mattace-Raso, N. van der Velde — 2011-12-01

Introduction: Recently in elderly, homocysteine alone has been shown to be a better predictor of cardiovascular mortality than models based on classical risk factors. The pathophysiological pathway is however still unclear. Current view is that increased thrombogenicity, increased oxidative stress and over-activation of redox-sensitive inflammatory pathways, leads to impaired endothelial function.

Central blood pressure (BP) is an independent predictor of worse outcome in young to middle age subjects screened for stage I hypertension

2011-12-01

Objective: The aim was to evaluate the association of central BP with target organ damage (TOD) and the risk of future hypertension in a cohort of subjects from the HARVEST study. Methods. We studied 305 stage I hypertensive subjects (mean age, 38±10 years). Central BP was obtained from radial artery tonometry. TOD included left ventricular hypertrophy and/or microalbuminuria.

Formation of new atherosclerotic plaques in well controlled rheumatoid arthritis depends on classical cardiovascular risk factors: A prospective longitudinal study

2011-12-01

Background: Rheumatoid arthritis (RA) is an independent risk factor for cardiovascular disease (CVD); RA patients demonstrate advanced pre-clinical carotid atherosclerosis compared to controls.

Central blood pressure (CBP) measurements in the Portuguese population: The Guimarães study (study to determine the cardiovascular risk of the population of Guimarães/Vizela: Prevalence of arterial stiffness and early vascular aging syndrome)

P.G. Cunha, P.N. Oliveira, J. Cotter, N. Sousa — 2011-12-01

We observed 1104 subjects of the Portuguese population coming from two northern adjacent cities: Guimarães and Vizela. They were randomly selected to be included in a cohort representative of age and gender distribution. We evaluated their blood pressure (BP) (mean three measurements), height, weight, lipidic profile, fasting glucose, HbA1c, serum creatinine, microalbuminuria (occasional sample) and CBP measurements (Sphygmocor®).

Relationship between media to lumen ratio of subcutaneous small arteries and wall to lumen ratio of retinal arterioles evaluated non invasively by scanning laser Doppler flowmetry

2011-12-01

Structural alterations of subcutaneous small resistance arteries, as indicated by an increased media to lumen (M/L) ratio, are frequently present in hypertensive and/or diabetic patients, and may represent the earliest alteration observed. In addition, M/L of small arteries evaluated by micromyography has a strong prognostic significance; however its extensive evaluation is limited by the invasivity of the assessment, since a biopsy of subcutaneous fat is needed. Non-invasive measurement of wall to lumen (W/L) of retinal arterioles using scanning laser doppler flowmetry (SLDF) has been recently introduced (Harazny J et al, Hypertension 2007; 50:623-629). However, this new technique was never compared with micromyographic measurement, considered the gold standard approach.

Investigation of the effects induced on endothelial function by the human T2238C ANP gene molecular variant

2011-12-01

Objective: The T2238C ANP gene molecular variant has been related to increased risk of cardiovascular events. In-vitro investigations of its pathogenetic mechanisms demonstrated that the 2238C allele variant induced detrimental effects on endothelial cells through increased ROS production. Based on these observations we hypothesized that T2238C ANP gene variant could exert a pathogenic impact on endothelial function in-vivo.

Recombinant human erythropoietin alters subcutaneous resistance artery endothelial function through a mechanism involving oxidative stress and endothelin-1 in patients with stage 4 chronic kidney disease

2011-12-01

Objective: Recent studies have raised concern about the safety of recombinant human erythropoietin (RhuEPO) because of evidence of an increase in the risk of cardiovascular disease in chronic kidney disease (CKD) patients. In the present study we investigated the effect of RhuEPO on the function of resistance arteries isolated from CKD patients.

Paradoxical involvement of the endothelial mineralocorticoid receptor in platelet activation and vascular thrombosis in mouse

2011-12-01

Our aim was to investigate whether mineralocorticoid receptor (MR) overexpression in the vascular endothelium modifies the in vitro thrombin generation using thrombography and enhances the thrombotic risk in vivo. We used our mouse model with conditional overexpression of the MR in endothelial cells (MR-EC) (Nguyen Dinh Cat et al, FASEB J. 2010;24:2454-63).

Are retinal microvascular phenotypes associated with 1675G/A polymorphism in angiotensin II receptor-2 gene?

2011-12-01

Background: The X-linked AT2R G1675A polymorphism is located in the short intron 1 of the AT2R gene within a sequence motif conforming to a splice branch site. AT2R is expressed in the human retina, but no previous study examined the association between retinal microvascular phenotypes and the AT2R G1675A polymorphism.

An impaired role of epoxyeicosatrienoic acids contributes with altered NO and endothelin-1 pathways to conduit artery endothelial dysfunction in essential hypertension

J. Bellien, M. Iacob, D. Lucas, C. Monteil, I. Jouet, C. Thuillez, R. Joannides — 2011-12-01

Background: The mechanisms involved in the endothelial dysfunction of conduit arteries, which is an independent contributor to the high incidence of cardiovascular events during essential hypertension, remains to be fully elucidated.

Endothelium dependent and independent dilatation in different vascular beds

2011-12-01

Objective Several methods have been proposed for the evaluation of endothelial dysfunction in patients with cardiovascular risk factors. Whether the flow-mediated dilation (FMD) in medium size arteries is related to the vasodilating response to different agonists in small resistance arteries has not been adequately evaluated. Aim of the present study was to assess the endothelial dysfunction in subcutaneous small resistance arteries (response to acetylcholine, Ach or bradikinin, BK) and in the brachial artery (FMD) in normotensive subjects (NT), essential hypertensives (EHT), patients with primary aldosteronism (PA) and patients with type2 diabetes (DM). Methods 46 DM (20 F, age 39-77 yrs, 14 NT and 32 HT), 6 EHT (3 F, age 40-66 yrs), 6 PA (4 F, age 40- 57yrs), and 4 NT (2 F, age 16-64 yrs) underwent a biopsy of the subcutaneous fat. Small resistance arteries were mounted on a micromyograph and a concentration-response curve to Ach (from 10-9 to 10-5) and to BK (from 10-10 to 10-6) was performed. In all patients we measured, by a high resolution ultrasound, the brachial artery (BA) diameter at rest, during reactive hyperemia (5 mis of BA occlusion); BA flow velocity was measured by pulsed doppler

Endothelial function and renal vasodilation, but not arterial stiffness, are impaired in lean, normotensive patients with obstructive sleep-apnea

2011-12-01

Background: Patients with obstructive sleep apnea (OSA), a condition with a strong comorbidity with hypertension and obesity, exhibit an accelerated vascular aging and renal damage. The aim of the study was to evaluate endothelial function, arterial stiffness, and renal vasodilating response to glyceryl trinitrate (GTN), a new parameter of renal vascular damage, in lean, normotensive patients with OSA.

Damage accrual is associated with endothelial function detriment: A prospective cohort study

2011-12-01

Introduction: Our aim was to study endothelial function in a cohort of systemic lupus erythematosus (SLE) patients prospectively followed at our unit and to investigate its relation with disease activity and damage over time.

Mechanistic insights into the relationship between wave reflection and retinal artery flow pulsatility

2011-12-01

Background:Increased arterial stiffness is associated with a reduced buffering capacity of the large arteries, therefore predisposing the microcirculation to increased flow and pressure pulsatility. Previous data from our group have illustrated a positive relationship between aortic pulse wave velocity and an inverse relationship between wave reflection and retinal artery flow pulsatility.Therefore, the aim of this study was to investigate the macrovascular haemodynamic mechanisms involved in retinal artery flow pulsatility, by manipulation of wave reflection by Glycerol Trinitrate Nitrate administration.

Imaging of retinal arteriolar wall in vivo in humans

M. Paques, K. Gocho-Nakashima, O. Genevois, E. Plaisier, J.A. Sahel — 2011-12-01

Purpose: Adaptive optics (AO) is an opto-electronic technique improving lateral resolution of fundus images. Here we report a novel application of AO imaging, namely the visualization of the arteriolar wall in the human retina.

The interplay of endothelial function, inflammatory and oxidative status in HIV infection. Does antiretroviral therapy play a role?

2011-12-01

Purpose: HIV infection is linked to heightened cardiovascular risk; this is partly mediated through endothelial dysfunction. We investigated the interplay of endothelial function with markers of inflammatory and oxidation in two groups of HIV infected patients: on ART and naïve to ART.

Altered microvascular responses to angiotensin II infusion indicating endothelial dysfunction in subjects with familial hypercholesterolemia

M. Ekholm, G. Jörneskog, H. Wallén, J. Brinck, T. Kahan — 2011-12-01

Purpose: Angiotensin II (ANG) is implicated in the development of cardiovascular disease. We examined vascular responses to ANG in subjects with familial hypercholesterolemia (FH), a group at high cardiovascular risk.

Relation of heart rate variability to endothelial function in healthy subjects – Dependence upon cardiac cycle length

A. Pinter, T. Horvath, M. Kollai — 2011-12-01

In various diseased states reduced cardiac vagal modulation (CVM) is accompanied by impaired endothelial function. It is unclear whether CVM and endothelial function undergo dysregulation independently, or these systems affect each other negatively as a consequence of the disease process. Since the respective physiology is unclear, we aimed to investigate if such relationship between CVM and endothelial function exists in healthy subjects.

A comparison of arterial function of HIV infected (treated and never-treated) and uninfected black South Africans after five years: Pure study

2011-12-01

The prevention and treatment of hypertension is marginalized in South Africa by the overwhelming prevalence of HIV. HIV-1 infection and the treatment thereof paradoxically affect cardiovascular risk factors and may add to the cardiovascular risk of these individuals.

Rosuvastatin improves arterial wave reflection and pulse pressure amplification by restoring endothelial function

C. Ott, U. Raff, M.P. Schneider, R.E. Schmieder — 2011-12-01

Objective: One of the major indicators of intact endothelial function is basal nitric oxide (NO) activity. Further, is seems to be likely that statin therapy exerts beneficial effects on vascular function, at least in part via an improvement of NO bioavailability.

Bioactives of wild berries: Potential alternatives to vasodilator drugs

K.S. Bhullar, H.P.V. Rupasinghe — 2011-12-01

Hypertension is described as one of the risk factors in arterial and cardiovascular health. With increasing hypertension risk in all age groups and side-effects of vasodilator drugs, need for an effective natural cure is crucial. Wild berries provide valuable biologically active phytochemicals which can also neutralize reactive oxygen species (ROS) that are pathological mediators in many chronic diseases including hypertension. Present research was carried out to study the total bioactive content and antioxidant capacity of ethanol extracts of wild berries and their ability to inhibit angiotensin converting enzyme (ACE) which is principal blood pressure regulating enzyme. Among the investigated five species of cloudberry (Rubus chamaemorus L.), crowberry (Empetrum nigrum), blueberry (Vaccinium corymbosum), cranberry (V. macrocarpon), partridgeberry (V. vitis-idaea), the highest anthocyanin content was found in early harvested crowberry while late harvested fruit of lingonberry exhibited the highest antioxidant capacity and phenolic content (p≤0.05). The ACE inhibition by berry extracts was measured by using a florescence based assay at presence of histidine –L-hippuryl-L-histidine-chloride substrate. All the berry extracts showed a concentration responsive enzyme inhibition in vitro indicating effective ACE inhibition. However, partridgeberry and cranberry were among the most effective (p=0.05). This study has demonstrated potential cardiovascular health benefits of berries and further studies are warranted to confirm the results using cell lines, animal and clinical studies.

Effects of antihypertensive drugs on central blood pressure

D. Agnoletti, Y. Zhang, C. Borghi, J. Blacher, M.E. Safar — 2011-12-01

Background: Central blood pressure (BP) is considered a better predictor of cardiovascular events than brachial BP, and mechanisms influencing central BP are mostly related to reduction of arterial stiffness and/or reflected waves. Comparison between drugs on their effect in central hemodynamics has poorly been studied.

Effects of acetazolamide on blood pressure and pulse waveform changes induced by high altitude exposure

2011-12-01

Background: Exposure to high altitude (HA) may induce mountain sickness and increase blood pressure (BP) but little is known on the effects on arterial properties. Acetazolamide (AC) has been proposed to prevent and treat mountain sickness, but no information is available on its effects on cardiovascular parameters at HA. Our aim was to assess these issues in healthy volunteers acutely exposed to very HA.

Relation between haptoglobin phenotype and arterial stiffness in newly diagnosed untreated hypertensive patients

C. Strandhave, M. Svensson, K. Holdensen, C.M. Skov, H. Krarup, J.H. Christensen — 2011-12-01

Arterial stiffness is a valuable predictor of cardiovascular risk in essential hypertension. Arterial stiffness is affected by several factors including genetic polymorphisms. Moreover, increased arterial stiffness has been associated with oxidative stress. Haptoglobin (Hp) is an innate antioxidant which due to molecular heterogeneity forms three phenotypes: 1-1, 2-1, and 2-2. The antioxidant ability is phenotype dependent. In diabetes mellitus Hp 2-2 is a predictor of vascular complications but whether Hp 2-2 predicts vascular complications in essential arterial hypertension has not previously been examined.

The influence of antihypertensive treatment on arterial stiffness and arterial wall shear stress

M.W. Rajzer, W. Wojciechowska, M. Klocek, K. Kawecka-Jaszcz — 2011-12-01

The aim of the study was to compare the effects of 5 drugs representing different antihypertensive classes on arterial wall shear stress (WSS) and arterial stiffness in patients with essential arterial hypertension (HT).

Nitroglycerin effect on aortal augmentation and central augmentation index

M. Berzina, A. Krallisa, G. Latkovskis, M. Zabunova, I. Mintale, A. Erglis — 2011-12-01

Background: Nitroglycerin (NG) reduces the systolic blood pressure, pulse pressure and augmentation index. The aim of our study was to evaluate the effect of NG on aortal augmentation (AA) and central augmentation index (CAI) in patients with different significance of the angiographically proved coronary artery disease (CAD).

Treatment with tocilizumab improves arterial function in rheumatoid arthritis: A 6-months pilot study

2011-12-01

Background: Endothelial function and arterial stiffness are significantly worse in rheumatoid arthritis (RA) compared to healthy controls in part due to the high-grade inflammation. In non-RA subjects, elevated serum levels of interleukin (IL)-6 are associated with accelerated atherosclerosis. Objectives: To examine whether therapeutic blockade of IL-6 receptor by tocilizumab in patients with active RA improves endothelial dysfunction and increases arterial elasticity.

Effects of nitroglycerin to reduce aortic pressure augmentation may not be mediated by dilation of muscular arteries

H. Fok, M. Li, B. Jiang, P. Chowienczyk — 2011-12-01

Nitroglycerin (NTG) reduces aortic pressure augmentation (AP) and index (AIx), by a mechanism thought to involve a reduction in pressure wave reflection by selective dilation of muscular arteries. We examined this assumption by comparing effects of NTG with those of phentolamine (PHT) a vasodilator with little action on muscular arteries. Seven healthy subjects aged 35-62 were studied receiving PHT (1.12, 2.25 and 4.5 mg bolus/infusion i.v.) and NTG (90, 300, 900 μg i.v. infusion over 30 min) on separate occasions in a cross-over study. Central pressures (from radial tonometry) and carotid-femoral pulse wave velocity (cfPWV) were assessed using the SphygmoCor system. Brachial, carotid and abdominal aortic diameter were recorded by ultrasound. NTG (90 μg) reduced AIx from 22.2±5.5 to 13.7±5.7% (P<0.05) and PHT (4.5 mg) produced a similar reduction from 24.6±5.1 to 15.6±5.7% (P <0.05). These changes in AIx were observed in the absence of any significant fall in mean arterial blood pressure (MAP) or cfPWV. NTG (90 μg μg/min) produced a greater dilation of the brachial artery than of the carotid or aorta and vasodilation of the brachial artery by this dose of NTG was significantly greater than that by PHT (4.5 mg): 11±0.19 vs. 2.6±0.13% (P<0.01). These results suggest that, although actions of NTG are associated with dilation of muscular arteries, this is not necessarily the action leading to a reduction in AIx. Actions on other parts of the vascular tree and/or on ventricular ejection may be responsible for the reduction in AIx by NTG and PHT.

Stress calculations in 3D reconstructions of arteries: The influence of axial image resolution

2011-12-01

Computational modeling of the stress distribution in vulnerable atherosclerotic plaques facilitates identification of high stress locations which can be related to plaque rupture. The first step in doing 3D biomechanical stress simulations is to accurately re-create the artery geometry from histology or in-vivo imaging. This research investigated the influence of the axial sampling resolution of histology on the stress distribution in plaques.

Influence of plaque geometry on peak cap stress

2011-12-01

Introduction: Cap of an atherosclerotic plaque ruptures when mechanical stresses in the cap exceeds local strength. In this study, we investigated influence of plaque geometry on cap stresses.

The reservoir-wave paradigm introduces artefact into wave intensity analysis: A computer modelling and in vivo study

J.P. Mynard, D.J. Penny, M.R. Davidson, J.J. Smolich — 2011-12-01

Background: Wave intensity (WI) has traditionally been calculated from measured pressure and velocity waveforms. In the recently proposed reservoir-wave approach, wave intensity is calculated using excess pressure (WIRW), i.e. the difference between measured and reservoir pressures. Although it has been suggested that WIRW is more accurate than WI [1], this has not yet been validated in a system with known wave reflection properties.

Cardiovascular parameters other than mean arterial pressure are predictive of dynamic changes in aortic stiffness in the rat

M. Butlin, G. Lindesay, K.D. Viegas, I. Tan, A.P. Avolio — 2011-12-01

It has been observed that phenylephrine induced mean arterial pressure (MAP) changes in rats cause different values of aortic stiffness, measured by pulse wave velocity (PWV), at the same MAP during increasing, compared to decreasing pressure. The reason for this hysteresis in the MAP-PWV relationship is not understood. This study evaluates the influence of a variety of cardiovascular factors on PWV. Five, 12 week old Wistar-Kyoto rats were anaesthetised and two pressure sensors introduced into the thoracic and abdominal aorta. Pressure was increased with intravascular phenylephrine infusion (30μg/kg/min), and allowed to return to baseline following cessation of infusion. This was repeated following intravascular hexamethonium bolus (20mg/kg), blocking autonomic activity to quantify the role of the sympathetic system. PWV, thoracic MAP, pulse pressure, form factor, maximum slope of pressure (dP/dt, surrogate measure of cardiac contractility), and R to R interval from the electrocardiogram were calculated for each individual pulse. These variables along with hexamethonium presence, and dynamic MAP direction were entered into a stepwise linear regression model (dependent variable: PWV). MAP, R to R interval, sympathetic activity, pulse pressure, dynamic MAP direction and dP/dt were significant predictors (Table). The results indicate that cardiovascular parameters other than MAP, especially pulse pressure, and notably sympathetic activity and R to R interval, are predictive of PWV. MAP direction remained in the model, indicating that other factors are at play, or that the aorta displays a short term viscoelastic memory. Further studies are required to isolate each of these factors and their effect on PWV.

Characteristics of aortic stiffness in diabetic rats treated with vitamin D

2011-12-01

Background: Diabetes mellitus is associated with macrovascular complications characterized by increased aortic stiffness. Mechanisms of diabetes-induced vascular impairment include persistent activation of the inflammatory system that may be improved by the immunomodulatory effects of orally administrated vitamin D. This study aimed to examine the effects of diabetes on the elastic properties of the aorta and the protective effects of vitamin D treatment.

Mechanical properties and stresses in carotid arteries quantified using clinical data from normotensive and hypertensive humans

I. Masson, H. Beaussier, P. Boutouyrie, S. Laurent, J.D. Humphrey, M. Zidi — 2011-12-01

Objectives: To model the in vivo nonlinear mechanical behavior of human common carotid arteries (CCAs), to compute wall stresses and to deduce changes in wall micro-constituents (elastin-dominated matrix, collagen fibers, vascular smooth muscle cells (VSMC)) in normotensive subjects (NT) and hypertensive patients (HT).

On the relevance of a PPG based two pulse synthesis model for screening against coronary artery diseases

D. Goswami, B.P. Chatterjee, S. Ray, K. Chaudhuri, J. Mukherjee — 2011-12-01

Abstract: Arterial stiffness is an independent predictor for coronary artery diseases (CAD). Various methods to predict coronary artery involvement are known but most of them have limited applicability in large-scale population screening due to cost barrier [1].

Biomechanical study of aneurysm rupture

J. Kim, A. Romo, P. Badel, A. Duprey, J.N. Albertini, J.P. Favre, S. Avril — 2011-12-01

The rupture of aortic aneurysms is a catastrophic event that represents a major public health issue. It has received a large interest from the scientific community. However, only limited research has provided quantitative values of mechanical stresses that may assess the risks of rupture of aneurysms [1].

The semicarbazide-sensitive amine oxidase (SSAO): A new actor in atherosclerosis in the APOE mouse model?

N. Mercier, S. Taleb, B. Fève, S. Jalkanen, Z. Mallat, P. Lacolley — 2011-12-01

The expression of « semicarbazide sensitive amine oxidase » (SSAO), an enzyme which transforms primary amines into aldehydes, ammonia and hydrogen peroxide, increases during smooth muscle cell differentiation (VSMC) and is widely expressed in the media layer from the arterial wall. The SSAO has been implicated in LDL oxidation and in inflammation. We hypothesized that the absence of SSAO should prevent the development of atherosclerosis. The progression of the disease and the implicated mechanisms were studied in double ApoE/SSAO knock out mice (ApoE-/-SSAO-/-) established in the laboratory.

Galectin-3 is a potential mediator of aldosterone effects in vascular remodeling

2011-12-01

Background. Aldosterone (Aldo) plays a major role in extracellular matrix (ECM) remodeling leading to heart failure (HF), but the mechanisms remained unclear. Galectin-3 (Gal-3), a β-galactosidase-binding lectin, plays an important role in inflammation and HF. We investigated whether Gal-3 mediates Aldo-induced ECM remodeling in vascular smooth muscle cells (VSMCs) in vitro and in vivo.

Model based estimation of aortic pulse wave velocity

S. Wassertheurer, B. Hametner, T. Weber — 2011-12-01

The proposed model is inspired by the theoretical frameworks of (1) Moens-Korteweg, (2) Bramwell & Hill, (3) Waterhammer equation used in ARCSolver. All of the mentioned equations allow the determination of velocity in an elastic tube from a single point measurement. Whereby Moens-Korteweg consider the tension of the wall and the radius of the vessel as well as the viscosity of blood which can be assumed constant and near one in the human circulation for simplicity. It's now not really surprising that with increasing pressure both wall tension and wall radius will elevate. In younger age both parameters likely to the same extent and with only minor effects on PWV. With increasing age distensibility of the arterial wall degenerates. Subsequently an increase in pressure will not be compensated by a diameter change, even more tension within the wall will increase and PWV as well. All changes affect PWV non linear. Equation 2 rewrites equation 1 to consider observable variables like pressure and volume flow. Simply spoken, PWV is a result of pressure changes and volume displacement. In complex transmission line theory using Fourier analysis, the relation between arterial flow and blood pressure is described by the so called characteristic impedance (Zc) illustrated in the Waterhammer Equation (3). ARCSolver calculates (Zc) using an adopted Windkessel model. Determinants of ARCSolver-PWV are wall tension (impedance), aortic blood pressure and age.

Relation of aortic augmentation index to arterial and ventricular properties

B. Jiang, P. Chowienczyk, D. Hou, X. Zhou — 2011-12-01

Aortic augmentation index, the amount by which aortic pressure is “augmented” above the first systolic shoulder of the aortic pulse wave, expressed as a ratio of aortic pulse pressure, is thought to relate to arterial properties. In particular it has been cited as an index of “arterial wave reflection” related to arterial stiffness. However, it could also be influenced by the characteristics of ventricular ejection. The objective of the present study was to examine the relation of AIx to arterial stiffness and ventricular contraction-relaxation. We studied 74 asymptomatic subjects, aged 24-89 years, 7-15 subjects per decade) using an Aloka α10 ultrasound system with 3MHz cardiac probe to perform conventional echocardiography, obtain tissue Doppler ventricular velocities and mitral flow velocities. Using the same system with a 10MHz linear vascular transducer, ECG-referenced echo-tracking of the carotid and femoral arteries was used to obtain carotid augmentation index (AIx) and carotid-femoral pulse wave velocity (PWV). The relation of AIx to PWV and ventricular tissue velocities was examined using univariable and multivariable regression analysis. On multivariable analysis, entering age, mean arterial blood pressure and all measures correlated with AIx on univariable analysis (including PWV), AIx was independently negatively correlated only with heart rate and the ratio of diastolic to atrial mitral valve flow velocities (E/A). Together these variables explained 39% of the variability in AIx. These results suggest that AIx is more closely related to ventricular contraction-relaxation than to arterial properties.

Pre-pregnancy to early pregnancy changes in maternal cardiovascular physiology

A.A. Mahendru, C.C. Lees, T.R. Everett, I.B. Wilkinson, C.M. McEniery — 2011-12-01

Maternal heart rate, blood pressure and cardiac output change as early as 5-6weeks in pregnancy. However, most of the longitudinal studies assessing maternal haemodynamic adaptation have used late first trimester measurements as ‘baseline’ against which changes in normal and complicated pregnancies have been compared. Moreover, the extent of changes in maternal arterial stiffness and central haemodynamics very early in pregnancy is not known.

Frequent and widespread vascular abnormalities in human STAT3 deficiency

2011-12-01

Background: STAT3 deficiency is responsible for autosomal dominant hyper-IgE syndrome characterized by recurrent bacterial and fungal infections, connective tissue abnormalities, hyper-IgE and Th17 lymphopenia. Although vascular abnormalities have been reported in some patients, the prevalence, characteristics and etiology of these features have yet to be described.

The central hemodynamic response to postural stress is unfavourably altered in patients with type 2 diabetes mellitus

M.G. Schultz, R.E.D. Climie, S.B. Nikolic, K.D. Ahuja, J.E. Sharman — 2011-12-01

Background. An abnormal brachial BP response to postural stress is associated with increased risk of developing hypertension and stroke. However, the hemodynamic responses contributing to changes in central BP with postural stress are not well characterised, and we aimed to determine these in healthy controls (HC) and patients with type 2 diabetes (T2DM); in whom we hypothesised would have an abnormal postural response.

Effect of rosuvastatin on the echolucency of the common carotid intima–media thickness: The METEOR trial

2011-12-01

Objective: Echolucency of the carotid intima-media thickness (CIMT) is thought to reflect a high probability of lipid infiltration and is associated with increased cardiovascular risk factor levels, morbidity, and mortality. The present study assessed the effect of statins on echolucency of the common CIMT.

Relationship between the catalase RS 769214 SNP and carotid plaques in a Caucasian cohort

V. Nivet-Antoine, C. Labat, C.H. Cottart, X. Dulcire, J.L. Beaudeux, A. Benetos — 2011-12-01

Many conventional risk factors associated with the development of arterioatherosclerosis have been reported. Despite large scale epidemiological studies, about half the burden of atherosclerotic cardiovascular disease remains unexplained by such conventional factors, although risk factor modification (when possible) is associated with improved outcome. Oxidative stress, has an important role in endothelial cell pathophysiology, in different aspects of the vascular response to stretch or shear stress, and in vascular aging. By this way, age-accelerated atherosclerosis has been induced in catalase activity-deficient mice. On the opposite, overexpression of catalase leads to both a delayed installation of arteriosclerosis and an increased life span in a murine model. We previously reported that the rs769214 SNP in the catalase (CAT) gene promoter was associated with a defect of renutrition of an elderly malnourished population; the same SNP was also showed to be involved in the development of an essential high blood pressure in an Asian population. The aim of this study was to evaluate the relationship between this SNP and the existence of carotid plaques in a large cohort of Caucasian subjects issued from the ERA study. Subject were classified according to the presence of two rs769214 G allele (CAT1 haplotype). In our study, the carotid plaques are higher in number and existence in CAT2 haplotype carriers. This result remains after sex and age adjustment. In conclusion, our results indicate that CAT rs769214 SNP A allele may be a risk factor that contribute to carotid plaques in Caucasians.

Pressure and flow relations in the systemic arterial tree throughout development from neonate to adult

2011-12-01

Introduction: For the adult circulation, several models exist, describing pressures and flows throughout the arterial system. Such models allow studying the effect on hemodynamics of physiological and pathophysiological changes in the vasculature. Here we present a model encompassing the full range from neonatal to adult dimensions during normal growth (Figure, left).

Association of wave reflections and aortic stiffness with uterine artery doppler pulsatility index and risk of preeclampsia

T.R. Everett, A. Mahendru, C.M. McEniery, C.C. Lees, I.B. Wilkinson — 2011-12-01

Objectives: Arterial stiffness is increased in women with preeclampsia. Assessment of spiral artery transformation and successful placentation by uterine artery Doppler pulsatility index (UtAD PI) is a widely used screening tool for early-onset preeclampsia. We sought to determine whether there was a relationship between uterine artery Doppler impedance and aortic stiffness and arterial wave reflection.

Normalisation for wall shear stress stimulus improves accuracy in the assessment of glucose-induced changes in flow-mediated dilation

2011-12-01

Background: In healthy arteries, acute changes in wall shear stress (WSS) elicit a vessel dilation response, through endothelial NO-release and smooth muscle relaxation (flow-mediated dilation, FMD). Metabolic or pharmacologic agents might modulate FMD, but may also interfere with the transient WSS stimulus utilised to assess FMD. We hypothesized that glucose-induced changes in FMD can be detected with greater sensitivity by normalising FMD for the WSS stimulus.

Aortic/penile index is a marker of occult coronary artery disease in middle-aged hypertensive patients with erectile dysfunction

2011-12-01

Background: It has been reported that there is a strict correlation between hypertension, erectile dysfunction (ED) and coronary artery disease (CAD), but the importance of an index to predict CAD in hypertensive ED patients needs to be addressed.

Dissociation of cardiac remodelling and aortic stiffness indices as of cardiac/vascular risk, and their relationship to vitamin D3

R. Rezai, S. Anderson, N. Sattar, J.K. Cruickshank — 2011-12-01

Aims: To investigate if concentric cardiac remodelling is related to central aortic Pulse Wave Velocity (aPWV) and to circulating vitamin D3, in men of different ethnic groups and cardiac/ vascular risk.

Effect of carotid baroreceptor activation on ventricular function and central arterial hemodynamics: A case report based on invasive pressure-volume loop analysis

P. Segers, S.J. Vermeersch, R. Wachter, D. Georgakopoulos — 2011-12-01

Background: Carotid baroreceptor activation (CBA) is being explored as anti-hypertensive therapy in patient with resistant hypertension. In this study, we demonstrate the effect of CBA on cardiac performance and central arterial hemodynamics based on invasive data measured in a 78 year old male patient with resistant hypertension who also showed clinical symptoms of heart failure. Materials and methods Measurements were performed upon implantation of a CBA device (CVRx, Minneapolis, Mn), with a pressure-volume catheter inserted via the groin and advanced into the left ventricle (LV). Pressure-volume loops were acquired at baseline and with CBA (Figure-left). Upon catheter pullback, pressure recordings were made (baseline and CBA) in the aortic root (Figure-right). A flow waveform was derived from the volume data, and combined with the aortic root pressure to assess wave reflection via wave decomposition.

Arterial stiffness, wave reflections and pulse pressure amplification in metabolic syndrome

M.E. Safar, A.D. Protogerou, J. Blacher — 2011-12-01

Background: the metabolic syndrome (MetS), an important contributor of insulin resistance and cardiovascular risk, is defined by three or more of the following clinical characteristics: abdominal obesity, hyperglycemia, hypertension, hypertriglyceridemia and hypo-HDL-cholesterolemia.

Alkaline phosphatase and arterial structure and function in hypertensive African men: The SABPA study

2011-12-01

Background: Vascular calcification is believed to be due to the conversion of vascular smooth muscle cells into osteoblast-like cells and is associated with mortality. Since hypertension and related mortality in Africans is a concern, we investigated associations between a marker of osteoblastic activity, alkaline phosphatase (ALP), and measures of arterial structure and function in hypertensive African men.

Arterial stiffness is associated with the severity of atherosclerosis and serum osteopontin levels in patients with symptomatic peripheral arterial disease

2011-12-01

Background: Arterial stiffness is an independent predictor of vascular morbidity and mortality in the general population and in high-risk patients. Angiographic score (ASc) is closely related to the extent of atherosclerosis in patients with peripheral arterial disease (PAD). Osteopontin (OPN) is involved in the pathogenesis of atherosclerosis. The aim of the present study was to evaluate the association between arterial stiffness, ASc, and serum OPN in patients with symptomatic peripheral arterial disease.

The influence of the mean blood pressure on arterial stiffness parameters in rheumatoid arthritis and systemic lupus erythematosus women

A. Cypiene, J. Dadoniene, R. Rugiene, Z. Petrulioniene, A. Laucevicius — 2011-12-01

Introduction: The increased prevalence of premature atherosclerosis and stiffening of arteries in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) is well established.

Bronchoconstriction does not significantly alter central haemodynamics in healthy young adults

J.E. Sharman, J. Marrone, J. Walls, D.P. Johns, R. Wood-Baker, E.H. Walters — 2011-12-01

Background: Cardiovascular disease is the most frequent cause of death in people with chronic respiratory disease. Whether this association is due to shared comorbidities or adverse respiratory function exerting detrimental cardiovascular effects is unknown. This study aimed to determine the cardiovascular effect of methacholine-induced acute airway obstruction.

Maternal hemodynamics at 11–13 weeks of gestation and the risk of pre-eclampsia

A. Khalil, R. Akolekar, A. Syngelaki, M. ElKhaouly, K. Nicolaides — 2011-12-01

Background: Women who develop preeclampsia (PE) are at increased risk of cardiovascular disease and stroke in the subsequent decades. In individuals with cardiovascular disorders there is increased central aortic systolic blood pressure (SBPAo) and arterial stiffness, assessed by pulse wave velocity (PWV) and augmentation index (AIx). The aim of this screening study was to examine the potential value of assessment of SBPAo, PWV and AIx at 11-13 weeks’ gestation in identifying women who subsequently develop PE.

Additive effect of cardiovascular risk factors on carotid and aortic stiffness in essential hypertensive patients

2011-12-01

Background: The role of other cardiovascular risk factors (RF) on top of hypertension in worsening arterial elastic properties is still unknown. The aim of the study was to evaluate whether cardiovascular RF can influence aortic and carotid stiffness in essential hypertensive patients.

Chronic hypoxemia per se induces systemic vascular dysfunction in humans

2011-12-01

Cardiovascular (CV) morbidity and mortality are increased in patients suffering from diseases associated with chronic hypoxemia. The contribution of hypoxemia per se has proven difficult to determine, because these patients often present several additional CV risk factors. Chronic mountain sickness (CMS) is characterized by chronic hypoxemia, affects subjects with a low CV risk profile and thereby provides a unique opportunity to study the independent effects of chronic hypoxemia on vascular function. We measured arterial oxygen saturation (SaO2), flow-mediated dilation (FMD) of the brachial artery, carotid-femoral pulse wave velocity (PWV) and carotid intima-media thickness (IMT) in 23 CMS patients and 27 controls permanently living at 3600 m. The main new finding was that CMS patients (SaO2 83±3 vs. 90±3% in controls, P<0.0001) displayed marked systemic vascular dysfunction as evidenced by decreased FMD (4.6±1.2 vs. 7.6±1.9%, P<0.0001) and increased PWV (10.6±2.1 vs. 8.4±1.0 m/s, P<0.001) and IMT (690±120 vs. 570±110 μm, P=0.001). Oxygen administration almost completely restored FMD in CMS patients but had no effect in controls. These data demonstrate for the first time that chronic hypoxemia per se induces systemic vascular dysfunction in humans. We speculate that improving arterial oxygenation per se has favorable effects on CV morbidity and mortality in chronically hypoxemic patients.

Carotid and aortic stiffness in patients with heterozygous familial hypercholesterolemia

2011-12-01

Aim: The role of plasma cholesterol in impairing arterial function and elasticity remains not completely defined. We evaluated the arterial stiffness, measured locally in the common carotid artery with a high-precision echo-tracking, and aortic stiffness, measured with carotid-femoral pulse wave velocity (PWV) (the «gold-standard» measurement of arterial stiffness), in patients with never-treated heterozygous familial hypercholesterolemia (FH).

TIMP1 plasma levels are correlated with arterial stiffening process

2011-12-01

Introduction: Arterial stiffness and left ventricle hypertrophy are associated with a decrease in collagen type1 degradation. Aim of our study was to address whether an increase in plasma levels of metalloproteinases-1 (MMP1, responsible for collagen type1 degradation) and her tissue inhibitor (TIMP1) are correlated to the presence of subclinical vascular organ damage (VOD) as defined by ESH-ESC Hypertension guidelines.

Pulmonary arterial hypertension and arterial stiffness

2011-12-01

Background: Endothelium plays an important role in the development and progression of Pulmonary Arterial Hypertension (PAH), independently of its aetiology. Little is known on derived central blood pressure (CBP) and arterial stiffness in PAH. The aim of this study was to describe CBP and arterial stiffness as measured by PWA (Aix).

Central pulse pressure and aortic stiffness determine renal artery flow: Hemodynamic mechanism proposed for microalbuminuria

J. Hashimoto, S. Ito — 2011-12-01

A significant link has been shown between aortic stiffening and renal microvascular damage, but the underlying mechanism is not fully understood. We hypothesized that alterations in central and renal hemodynamics are responsible for this link. In 133 patients with hypertension, pressure waveforms were recorded on the radial, carotid, femoral and dorsalis pedis arteries with applanation tonometry to estimate the aortic pressures and aortic (carotid-femoral) and peripheral (carotid-radial and femoral-dorsalis pedis) pulse wave velocities (PWVs). Flow-velocity waveforms were recorded on the renal segmental arteries with duplex ultrasound to calculate the resistive index (RI) as [1 – (end-diastolic velocity/peak systolic velocity)], and on the femoral arteries to calculate the reverse/forward flow index and diastolic/systolic forward-flow ratio. (Micro)albuminuria was defined as urinary albumin/creatinine ratio (UACR) ≥30mg/gCr. The renal RI (mean, 0.65±0.07) was strongly correlated (P<0.001) with the aortic pulse pressure (r=0.62), incident pressure wave (r=0.55), augmented pressure (r=0.52) and aortic PWV (r=0.51), though not with the mean arterial pressure or peripheral PWVs. The correlations remained highly significant after adjustment for confounders including age, sex, hypercholesterolemia, diabetes and serum creatinine. The renal RI was inversely correlated with the femoral reverse and diastolic forward flow indices. Both aortic pulse pressure and renal RI correlated with UACR independently of the confounders. Each 0.1 increase in renal RI was associated with a 4.6-fold increase in the adjusted relative risk of (micro)albuminuria. In conclusion, increased aortic pulse pressure due to aortic stiffening causes renal microvascular damage through altered renal hemodynamics resulting from increased peripheral resistance and/or increased flow pulsation.

Ambulatory blood pressure correlates positively with cognitive scores in elderly people with chronic kidney disease (CKD) and cardiovascular disease

P.H. Thompson, J. Rusted, L.A. Tomlinson, M. Ford, K.A. Davies, J.E. Wright — 2011-12-01

Background: Studies have linked low blood pressure (BP) with adverse outcomes in CKD. Hypertension is treated to reduce cardiovascular events, however this may compromise cerebral perfusion by excessive lowering of blood pressure.

Pulse pressure is a strong and independent predictor of incident atrial fibrillation in type 2 diabetic patients

F. Valbusa, S. Bonapace, G. Targher, L. Zenari, G. Arcaro — 2011-12-01

Introduction: Atrial fibrillation (AF) is the most common cause of chronic arrhythmia in adults and is associated with an increased risk of mortality and stroke. Pulse pressure (PP), as a surrogate measure of aortic stiffness, is an important risk factor for incident AF in the general adult population. Currently, there is no information about the possible role of PP in the development of FA in people with type 2 diabetes mellitus (DM), who are at high risk of developing FA.

Gestational hypertension – An overlooked indicator for future cardiovascular risk

K.L. Miles, Y. Yasmin, J.R. Cockcroft, C.M. McEniery, I.B. Wilkinson — 2011-12-01

Background: Hypertension in pregnancy affects 3-8% of women in the UK, accounting for ∼ 6 maternal deaths each year, foetal growth restriction, prematurity and still birth. Both gestational hypertension (GHT) and pre-eclampsia (PET) are associated with increased cardiovascular (CV) risk in later life. Commonly, research excludes GHT or fails to investigate it separately to PET. Our study explores the haemodynamic consequences in later life, of hypertension in pregnancy.

Pulse timing differential as a measure of arterial stiffness

L.W. Winchester, N.Y. Chou — 2011-12-01

A simple measurement technique for the estimation of the dilation of the brachial artery has been developed from a comparison of measurements of pulse timing in a raised arm and a control arm kept at heart level. The artery expands in the raised arm leading to a decrease in blood velocity. An estimate of the dilation of the brachial artery is obtained from the assumption that the flow in the raised arm is unchanged due to the position of the arm. The pulse timing difference measured at similar points in the two arms (index finger or wrist) is due to the dilation of the artery. The square of the radial dilation d is given by the length of the brachial artery divided by the product of the systolic blood velocity in the control arm times the observed pulse timing difference. Measurements were obtained by placing transducers on the index fingers of both hand and the lower leg of the subject. Measurements are recorded at a 1 kHz rate using a laptop computer. Initially, the subject places both hands at heart level. After a period of 1 minute, the right hand is raised at an angle of 45° and supported by a platform. Pulse timing measurements are computed using the two sensors on the hands and the pulse wave velocity is computed using the left hand and leg sensors. Simultaneous measurements of pulse wave velocity are inversely correlated with the pulse timing difference.

Vascular explorations of patients with Erdheim Chester disease

D. Rosenbaum, F. Rached, F. Cohen, J. Haroche, X. Girerd — 2011-12-01

Objectives: To study structural and functional alterations of arteries in patients with Erdheim-Chester disease, a rare acquired idiopathic histiocytosis characterized by a circumferential fibrosis of the aorta and its main branches.

Relationship between wave reflection and renal vascular damage in hypertensive patients

F. Stea, M. Sgrò, R.M. Bruno, G. Cartoni, S. Armenia, L. Ghiadoni, S. Taddei — 2011-12-01

Background: Arterial stiffness reduces buffering capacity, exposing the microcirculation to increased pulsatility. Wave reflection could be protective by reducing pulsatility transmitted to low resistance vascular beds such as the brain or the kidney, as suggested by recent data in retinal circulation. Therefore we explored the relationship between wave reflections, arterial stiffness, and renal resistive index.

The method of distance measurement and torso length influences the relationship of pulse wave velocity to cardiovascular mortality

2011-12-01

Background: The method of estimating distance traveled by the pulse wave, used in the calculation of pulse wave velocity (PWV), is not standardized. Our objective was to assess whether different methods of distance measurement influenced the association of PWV to cardiovascular mortality in hemodialysis patients.

In-vivo assessment of the accuracy of carotid strain estimates derived from ultrasonic wall tracking

A. Swillens, L. Lovstakken, J. Degroote, G. De Santis, J. Vierendeels, P. Segers — 2011-12-01

Background: Ultrasonic wall tracking is a common tool in cardiovascular screening, where it is applied to assess arterial diameter distension waveforms. However, using multiple tracking points within the arterial wall and under the assumption of planar deformation, circumferential and radial strain can be obtained as εθθ=∆D/D and εrr=∂∆D/∂D.

The pressure dependence of arterial stiffness as a novel vascular marker determined from PWV and brachial BP taken at different arm heights

G. Schillaci, B. Gavish, G. Pucci, L. Settimi, E. Mannarino — 2011-12-01

Background: The increase of arterial stiffness with blood pressure (BP) reflects the nonlinear increase of arterial pressure with volume. Stiffness can be represented by the square of the pulse wave velocity (PWV), and is currently measured for diastolic BP (DBP). By analyzing the changes in DBP and diastolic PWV (PWVd) induced by changing arm position, we evaluated a linear relation between stiffness and DBP in an individual subject.

Relationship between aortic stiffness and a local pulsatile indice from the peripheral cutaneous microvasculature

E. Guerreschi, A. Humeau, S. Bricq, M. Collette, P. Meignan, G. Leftheriotis — 2011-12-01

Purpose: Increase in arterial stiffness could increase the transmission of pulsatile flow energy and potentially damage the downstream microcirculation. The study of changes in the microcirculatory pulsatility could help to improve our understanding on the deleterious effect of the upstream arterial stiffness. To achieve this goal, we studied the relationship between aortic stiffness, local stiffness (β indice) and distensibility (Ep) of carotid and a local microcirculatory pulsatility index (μFP).

Validity and reproducibility of a new method to estimate central blood pressure from the upper arm cuff oscillometric signal

R.E.D. Climie, M.J. Schultz, S.B. Nikolic, K.D.K. Ahuja, J.W. Fell, J.E. Sharman — 2011-12-01

Background: Central BP is an independent predictor of mortality. Current methods for non-invasively estimating central BP are operator-dependent and require skill to obtain quality recordings. The aims of this study were firstly, to determine the validity of an automatic, upper arm oscillometric cuff method for estimating central BP (OCBP) by comparison with the non-invasive reference standard of radial tonometry (TCBP). Secondly, we sought to determine the intra-test and inter-test reproducibility of OCBP.

pOpscore: A new index to evaluate arterial ageing independently of arterial blood pressure

M. Hallab, J.M. Boin, M. Tramblay, P. Chevalet — 2011-12-01

Hypothesis: PWV don't correlate with age in the upper limb but in the aorta and lower limb. Aim: To study the relationship between ageing and indices based on pulse wave transit time (PWTT) between the toe and the finger.

‘Ambulatory’ aortic pulse wave velocity is highly reproducible and independently correlates with kidney function in older men

L.J. Keith, M.A. Keske, S. Rattigan, J.E. Sharman — 2011-12-01

Introduction: Aortic pulse wave velocity (PWV) independently predicts end-organ damage and mortality. However, these relationships have only been assessed at rest. Considering light exercise (‘ambulatory’) conditions better represent chronic BP exposure, we developed a technique to approximate ambulatory aortic PWV (AaPWV). This study aimed to determine the reproducibility of the technique and relation of AaPWV to end-organ damage.

Waiting a few extra minutes before measuring central blood pressure potentially has important clinical and research ramifications

S.B. Nikolic, J.E. Sharman, W.P. Abhayaratna — 2011-12-01

Background: Clinic brachial BP averaged over 10 minutes correlates more strongly with out-of-office BP compared with BP recorded after the recommended 5 minutes rest. Central BP is a stronger predictor of mortality than brachial BP. However, the clinical value of measuring central BP after 5 compared with 10 minutes rest has never been assessed and was the aim of this study.

Comparison of SphygmoCor and vicorder devices for carotid-femoral PWV measurement in the second trimester of pregnancy

T.R. Everett, A. Mahendru, C.M. McEniery, C.C. Lees, I.B. Wilkinson — 2011-12-01

Objectives: Carotid-femoral pulse wave velocity (cfPWV) is considered the gold standard measurement for assessment of aortic stiffness. cfPWV is increased in women at risk of developing, and those with, preeclampsia. We aimed to compare measurements obtained by SphygmoCor and Vicorder devices that use ECG/tonometry and compression techniques, respectively.

Retinal pulse wave velocity in young normotensive and mildly hypertensive subjects

K. Kotliar, H. Hanssen, K. Eberhardt, M. Halle, U. Heemann, M. Baumann — 2011-12-01

Hypertension is characterized by microvascular remodeling resulting in an increased wall/lumen ratio. Increased microvascular stiffness contributes to an increase in wall/lumen ratio. We aimed to investigate the possibility to transform the measurement of macrovascular stiffness into a microvascular environment. We assessed retinal pulse wave velocity (rPWV) non-invasively in 65 male normoalbuminuric normotensive to mildly hypertensive subjects (age: 28.7±6.0 years). Time dependent alterations of retinal arterial diameter were measured by the Dynamic Vessel Analyzer. The data was filtered and evaluated by methods of signal analysis and rPWV was computed using three different methods. ‘Method1’ used filtration at heart rate (HR), ‘Method2’ filtered at higher HR multiples and ‘Method3’ used additionally linear fit for data averaging. Besides, office blood pressure (BP) and urinary albumine/creatinine ratio were assessed. ‘Method1’ was not associated with BP, while both methods applying filtration at high HR multiples showed a strong association with systolic BP throughout the cohort (r=0.49, r=0.63 P<0.001). Based on the highest association, ‘Method3’ was proposed to characterize rPWV. As the cohort was divided according to BP, mildly hypertensive patients showed significantly higher rPWV (1243±694 units/second) than subjects with high-normal BP (786±486 units/second, P<0.01) or normotensive subjects (442±148 units/second, P<0.001). Applying methodological principles for aortic PWV we consider rPWV as a non-invasive measure of microvascular stiffness. Our data suggests that filtration at higher HR multiples and linear fit result in strong association with BP. As our study was performed in normoalbuminuric subjects, rPWV may add detailed insights to early microvascular pathophysiology, potentially beyond microalbuminuria.

Correlation of pulse wave velocity and angiographically proved coronary artery stenosis

M. Berzina, A. Krallisa, G. Latkovskis, M. Zabunova, I. Mintale, A. Erglis — 2011-12-01

Background: Carotid-femoral pulse wave velocity (PWV), a direct measure of aortic stiffness, has become increasingly important for total cardiovascular risk estimation. The aim of our study was to evaluate the correlation of PWV among the other cardiovascular risk factors with significance of the angiographically proved coronary artery disease (CAD).

Impact of calibration on estimates of central blood pressure

2011-12-01

Methods: We included 122 patients with type-II-diabetes and hypertension. They were characterized as having controlled (CH), uncontrolled (UH) or resistant (RH) hypertension based on ambulatory blood pressure measurement and number of antihypertensive agents. CBP was estimated using Sphygmocor. We calibrated the radial pressure wave as recommended by the manufacturer using brachial systolic (BSBP) and diastolic (BDBP) BP and used the generalized transfer function for estimation of the aortic pressure waveform. Afterwards we recalibrated the radial pressure wave using BDBP and mean arterial pressure (BMAP). Data were analyzed offline in customized software.

Which estimate of mean arterial pressure is to be used for adjustment for pulse wave velocity?

2011-12-01

Methods: Patients with hypertension and type-II-DM were included. They were characterized as having controlled (CH), uncontrolled (UH) or resistant hypertension (RH). Patients with UH and RH received intensified antihypertensive treatment for six months.

Effect of body position on the measurements of central hemodynamic parameters: “Please have a sit?” or “Please lie down?”

2011-12-01

Background: Estimation of aortic pressure waveform provides clinical information regarding BP cardiovascular risk additional to the brachial blood pressure (BP). The effect of body position on central haemodynamics (BP, pulse pressure (PP) amplification (amp), augmentation index (AIx), augmentation pressure (AP), subendocardial viability ratio (SVR) have never been investigated. Aim/design: to investigate in a randomized cross over study changes in both the peripheral and central haemodynamics in supine and sitting position. Methods: Sixty one subjects referred for BP assessment were examined (36 males, mean age 50±12 yrs). Brachial and aortic waveforms were assessed in sitting and supine position. In each position: triplicate brachial BP measurements were performed; then 2 consecutive aortic pressure waveforms were estimated by applanation tonometry of the radial artery - pulse wave analysis and the use of transfer functions (Sphygmocor). The average of the last 2 brachial BP recordings was used in statistical analysis and for peripheral waveforms calibration. Results: Mean arterial BP did not differ significantly between the sitting and supine position (table). Brachial and aortic SBP, PP, AP, AIx were significantly higher in the supine position whereas DBP and PP amplification (ratio: brachial/aortic PP) significantly smaller. Moreover, significant alterations were observed in heart rate, ejection duration and SVR. Conclusions: Mean BP remained unchanged but the pulsatile BP component was higher in the supine position. This was more pronounced in the aorta, as shown by PP amplification, in part due to alterations in heart rate, wave reflections leading to alterations in coronary perfusion.

Determination of carotid and femoral wave speed and distensibility in a healthy population using a new non-invasive technique

A. Borlotti, S. Vermeersch, E. Rietzschel, P. Segers, A.W. Khir — 2011-12-01

In this work, carotid and femoral distensibility were assessed in the Asklepios study population. Local wave speed was determined with a new non-invasive technique based on velocity (U) and diameter (D) measurements (lnDU-loop) [1]. Distensibility was calculated using c and the Bramwell-Hill equation, and changes were studied with respect to age and gender.

Carotid artery cross-sectional area and stiffness non-linearity as markers of vascular ageing

2011-12-01

Background: Artery wall ageing involves elastic fibre loss and increased fibrosis, leading to dilatation and increased artery wall stiffness. Notably, the associated gradual transfer of tensile stresses from elastic to stiffer components in the wall will likely increase non-linear elastic behaviour of the vessel wall. We investigated whether age is indeed a determinant of carotid artery cross-sectional area (CSA) and stiffness non-linearity; the latter being quantified as the difference between systolic and diastolic pulse wave velocity: ΔPWV, in m/s (Figure).

Comparison of arterial stiffness assessed by arteriograph with arterial stiffness assessed by applanation tonometry and echotracking: A clinical study

M. Alivon, E. Bozec, A. Herbert, S. Laurent, P. Boutouyrie — 2011-12-01

Introduction: Large artery stiffness is recognized as a strong, independent marker of cardiovascular risk, mainly through aortic pulse wave velocity (PWV). Arteriograph is a new non-invasive oscillometric method, which estimates aortic PWV through brachial pressure wave analysis. In a previous study, Trachet et al. (Annals of Biomedical Engineering 2010) have shown, using a numerical model of arterial tree, that Arteriograph measured a brachial stiffness instead of aortic stiffness.

Effects of cardiac motion on the left coronary artery flow rate

A. Hashemifard, N. Fatouraee — 2011-12-01

The aim of this work was to investigate the effects of physiologically idealized cardiac-induced motion on flow rate in human left coronary arteries. The blood flow rate were numerically simulated in a elastic modelled left anterior descending coronary artery (LAD) having a uniform circular cross section of 3.6 mm diam. Blood was considered to be a non-Newtonian fluid and Arterial motion was specified based on monoplane physiologically idealized bending. Simulations were carried out with dynamic pressure difference conditions between inlet and outlet in both fixed and moving LAD models, to evaluate the relative importance of LAD motion, flow rate, and the interaction between motion and time-averaged flow rate. LAD motion was caused variations in time-averaged flow rate magnitude about 30% of the fixed models. There was significant variability in the magnitude of this motion-induced flow variation. However, the magnification of time-averaged flow rate is depending to specification of the cardiac motion. Furthermore, the effects of pressure pulsatility dominated LAD motion induced effects; specifically, there were local flow variation and secondary flow in the simulations conducted in moving LAD models. LAD motion has big effect on time-averaged flow rate and secondary flow. Therefore, the hemodynamic effects of LAD motion can not to be ignored as a first approximation in modelling studies.

Vascular accesses for haemodialysis in the arm cause greater reduction in the carotid-brachial stiffness than those in the forearm: Study of gender differences

2011-12-01

Purpose: to evaluate in chronically-haemodialysed patients (CHP) if, 1) the vascular access (VA) position (arm or forearm) is associated with differential changes in upper-limb arterial stiffness; 2) differences in arterial stiffness exist between genders associated with the VA; 3) the vascular substitute (VS) of choice, in biomechanical terms, depends on the previous VA location and CHP gender.

The stimulation of the visual cortex resulted in the blood flow increase in the entire posterior circulation territory

A.Yu. Vishnyakova, O.B. Kerbikov, S.E. Lelyuk, V.G. Lelyuk, V.I. Skvortsova — 2011-12-01

We hypothesized that visual stimulation results in blood flow increase in all main arteries of the posterior circulation territory (PCT). In an attempt to establish relation between visual stimulation and blood flow, we assessed visually evoked cerebral blood flow response (VEFR) in vertebral (VA), basilar (BA) and posterior cerebral arteries (PCA).

Use of the right versus the left carotid artery: Is there any difference when measuring aortic pulse wave velocity?

M. Dzeko, C.D. Peters, K.D. Kjaergaard, J.D. Jensen, B. Jespersen — 2011-12-01

Background and aim: Aortic pulse wave velocity (aPWV) derived by use of applanation tonometry is a non-invasive method for assessment of arterial stiffness. Current methodology in aPWV assessment dictates ipsilateral measurements. However, the carotid arteries (CA) branch slightly differently from the aorta towards the right and left side of the neck. Theoretically, using right or left CA could influence aPWV results.

Aortic pulse wave velocity, estimated with a simplified method based on radial waveforms and body height, predicts cardiovascular events

2011-12-01

Background: The prognostic role of aortic pulse wave velocity (aPWV) is well known. Its non-invasive determination (carotid-femoral PWV) is inconvenient, and easier yet accurate methods could be of value to facilitate the adoption by clinicians.

Relation of mean and pulsatile blood pressure components to atherosclerosis and arteriosclerosis: A 10-year follow-up study

M. Cecelja, B. Jiang, T. Spector, P. Chowienczyk — 2011-12-01

Background: Blood pressure (BP) can be separated into mean arterial pressure (MAP) and pulsatile (pulse pressure, PP) components which may relate differently to atherosclerosis and arteriosclerosis. The aim of the study was to examine the association between longitudinal measures of MAP and PP (central and peripheral) with measures of atherosclerosis and arterial stiffness.

Subclinical measures of atherosclerosis associate differently with prevalent coronary heart disease in Indian Asians and Europeans

T. Tillin, C. Park, K. March, E. Coady, N. Chaturvedi, A. Hughes — 2011-12-01

Background: Globally Indian Asians have increased risk of coronary heart disease (CHD). Subclinical markers of atherosclerosis, such as carotid intima media thickness (CIMT) and coronary artery calcification scores (CACS), play an increasingly important role in risk prediction, but need to be validated in different ethnic groups.

Aortic stiffness is associated with albuminuria in the general population

2011-12-01

Background: Albuminuria has been associated with increased cardiovascular risk. We hypothesised that this may be mediated through increased central arterial stiffness and subsequent transmission of pulsatile strain to the renal microvasculature.

Determination of the best ankle brachial index threshold values for the routine detection of a significant lower limb arterial stenosis using an automated device

2011-12-01

Objectives: To assess the prevalence of significant lower limb arterial stenosis in a population of patients with an increased cardiovascular risk and to determine the best ankle brachial index (ABI) threshold value for its detection.

Gender difference in cardiovascular risk: Role of blood pressure amplification

V. Regnault, P. Lacolley, M.E. Safar, F. Thomas, B. Pannier, N. Danchin — 2011-12-01

Carotid (C) pulse pressure (PP) is constantly lower than brachial (B) PP, but is a more powerful predictor of CV risk than B-PP. The C/B-PP ratio is marker of PP amplification. The objective was to explore whether the role of C/B-PP ratio for all-cause and CV mortality is different between men and women.

Blood pressure control and early cognitive impairment screening

T. Yaneva, R. Tarnovska, L. Traykov — 2011-12-01

Purpose: The purpose of this study is to find whether achieving optimal blood pressure (BP) control could prevent mild cognitive impairment (MCI), and whether we should conduct MCI screening routinely in patients (Pts) with hypertension (HT).

Preclinical markers of carotid atherosclerosis and cardiovascular risk assessed by the ESH/ESC scale (2003, 2007)

T.V. Balakhonova, S.J. Urazalina — 2011-12-01

Objective: The SCORE scale is applied to assess the total cardiovascular risk. Risk stratification system of Recommendations (ESH)/(ESC) (2003, 2007) unlike the SCORE scale allows to give a more accurate assessment of the risk range with using results of tool methods of investigation.

Pulse wave analysis reveals that myocardial ischaemia is not likely to explain the ‘J-curve’ association between diastolic blood pressure and mortality

M.G. Schultz, W.P. Abhayaratna, J.E. Sharman — 2011-12-01

Background: There is a well-established ‘J-curve’ relationship between brachial DBP and mortality. A purported, although unconfirmed mechanism for the “J-curve” is reduced myocardial perfusion due to low DBP. However, we hypothesised this would be unlikely because DBP may be a poor marker of myocardial perfusion. This study aimed to determine the relationship between DBP and subendocardial perfusion in patients with and without coronary artery disease (CAD).

Renal function does not modify predictive value of central pulse pressure and pulsatility in patients with CAD

2011-12-01

Background: The differences between central and peripheral blood pressure (BP) values have been known for decades. Although the predictive value of central BP in coronary patients with impaired renal function has not been studied so far. Therefore, the aim of the study was to assess the influence of renal function on the predictive value of ascending aortic pulse pressure (PP) and pulsatility (the ratio of PP to mean BP) in patients with coronary artery disease.

Normal values of pulse wave velocity and augmentation index among omani volunteers; preliminary report

K.M.S. AlHashmi, M. AlHooti, A.H. Al-Ghafri, Z.N. Al-Rashdi, M.O. Hassan — 2011-12-01

Background: Stiffness of large arteries has been found to be an independent predictor of adverse cardiovascular events in the general population, in patients with essential hypertension, diabetes mellitus and end-stage renal disease. Of the several indices used to reflect arterial stiffness, aortic pulse wave velocity (AoPWV) is considered to be the gold standard. Determining the normal distribution of AoPWV and AIx of a population is important to apply them clinically. This study therefore aims at determining normal values for arterial stiffness indices in normal Omani subjects.

Central haemodynamics could explain the inverse association between height and cardiovascular mortality

J.C. Reeve, W.P. Abhayaratna, J.E. Sharman — 2011-12-01

Introduction: Mechanisms underlying the inverse relationship between height and cardiovascular mortality are unknown, but could be related to central haemodynamics. This study aimed to determine the relation of height to central and peripheral haemodynamics.

Which arterial stiffness parameter is the best predictor of cardiovascular mortality in hemodialysis patients?

2011-12-01

According to previous studies different parameters characterize arterial stiffness relate to cardiovascular mortality in patients on haemodialysis. However, its relative prognostic value and the optimal time of measurement have not previously been examined in one cohort.

C-reactive protein and markers of arterial stiffness in high cardiovascular risk patients

2011-12-01

Introduction: The aim of the study was to investigate the relationship between C-reactive protein (CRP) and markers of arterial stiffness. Methods: We have analyzed the data of 3163 high cardiovascular risk patients selected from a larger cohort of patients inspected in Vilnius University Hospital Santariškių Klinikos primary prevention cardiovascular unit. The criteria for inclusion was low value of CRP (<5 mg/l). The mean age of the selected sample was 54.03+/-6.10. Almost two thirds of them were females (65.7%). We divided all patients into two groups. The first group consisted of patients having CRP below 2 mg/l (n=2041), whereas the second group consisted of patients having CRP no less than 2 mg/l (n=1122). After that, these groups were compared with respect to the following markers of arterial stiffness: augmentation index (AiX), flow mediated dilatation (FMD), femoral and brachial pulse wave velocities (PWV (femoral), PWV (brachial)). Only femoral PWV significantly differed between the groups: (8.69+/-2.68 (CRP<2 mg/dl) vs 9.00+/-1.59 (CRP≥2 mg/dl); p=0.003), and there were no differences with respect to other markers. Division of patients into groups with CRP<3 mg/l (n=2623) and CRP≥3 mg/l (n = 540) yielded the same results. There was a significant difference only with regard to femoral PWV (8.74+/-2.45 (CRP<3) vs. 9,12+/-1,56 (CRP≥3); p=0,004).

Measurement of arterial stiffness in the Portuguese population: The Guimarães study (study to determine the cardiovascular risk of the population of Guimarães/Vizela: Prevalence of arterial stiffness and early vascular aging syndrome)

P.G. Cunha, P.N. Oliveira, J. Cotter, N. Sousa — 2011-12-01

We observed 1104 subjects of the Portuguese population coming from two adjacent cities in the north: Guimarães and Vizela. They were randomly selected from the population to be included in a cohort representative of the age and gender distribution. We evaluated their age, sex, clinical history, blood pressure (BP) (mean of three measurements), height, weight, lipidic profile, fasting glucose, HbA1c, serum creatinine, microalbuminuria (occasional sample); we also performed Pulse Wave Velocity (PWV) measurements (Sphygmocor®).

Assessment of central haemodynamics and arterial stiffness in the community – Are we there yet?

2011-12-01

Background: The assessment of arterial stiffness and central pressures has been limited to specialised techniques and settings. New, more practical methods (ARCSolver) allow assessment using a standard brachial cuff. The objective was to assess the feasibility of central haemodynamics and surrogates of arterial stiffness from the ARCSolver in a community based setting.

Endothelial dysfunction and low-grade inflammation are associated with arterial stiffness in healthy adults over a 6-year period: The Amsterdam Growth and Health Longitudinal Study (AGAHLS)

2011-12-01

Endothelial dysfunction and low-grade inflammation are associated with cardiovascular disease. Arterial stiffening plays an important role in cardiovascular disease and thus may be a mechanism through which endothelial dysfunction and/or low-grade inflammation lead to cardiovascular disease. We investigated the associations between, on the one hand, biomarkers of endothelial dysfunction (soluble endothelial selectin, thrombomodulin and both vascular- and intercellular adhesion molecules 1 and von Willebrand factor) and of low-grade inflammation (C-reactive protein, serum amyloïd A, interleukin 6, interleukin 8, tumour necrosis factor α and soluble intercellular adhesion molecule 1) and, on the other hand, arterial stiffness over a 6-year period, in 293 healthy adults (155 women). Biomarkers were combined into mean Z-scores. Carotid, femoral and brachial arterial stiffness and carotid-femoral pulse wave velocity were determined by ultrasonography. Measurements were obtained when individuals were 36 and 42 years of age. Associations were analysed with generalised estimating equation and adjusted for sex, height and mean arterial pressure. The endothelial dysfunction Z-score was inversely associated with femoral distensibility [β(95%CI)-0.51(-0.95;-0.06)] and compliance coefficients [-0.041(-0.076;-0.006)], but not with carotid or brachial stiffness or carotid-femoral pulse wave velocity. The low-grade inflammation Z-score was inversely associated with femoral distensibility [-0.51(-0.95;-0.07)] and compliance coefficients [-0.050(-0.084;-0.016)], and with carotid distensibility coefficient [-0.91(-1.81;-0.008)], but not with brachial stiffness or carotid-femoral pulse wave velocity. Biomarkers of endothelial dysfunction and low-grade inflammation are associated with greater arterial stiffness. This provides evidence that arterial stiffening may be a mechanism through which endothelial dysfunction and low-grade inflammation lead to cardiovascular disease.

Characterization of the vasorelaxant mechanisms of endocannabinoid oleoylethanolamide in the bovine ophthalmic artery

M.R. Romano, A.D. Lograno, M.D. Lograno — 2011-12-01

Aim: To evaluate the vasorelaxant effect of oleoylethanolamide on isolated bovine ophthalmic arteries and to evaluate the possible mechanisms involved in relaxant responses. Methods: Ophthalmic arteries were isolated from bovine eyes and mounted in a wire miograph for isometric tension recording. The effects time- and concentration-dependent were assayed by addition of the oleoylethanolamide to the organ bath.

Different effects of plasma membrane calcium ATPase 4 (PMCA4) ablation and acute inhibition on contractility of isolated mouse mesenteric arteries

S. Lewis, C. Cobb, E. Cartwright, C. Austin — 2011-12-01

Plasma Membrane Calcium ATPases (PMCAs’) are calcium extrusion pumps which may also modulate signal transduction. The most abundant PMCA isoform in vascular smooth muscle is PMCA4 however its effect on arterial constriction is unclear. Here, PMCA4 ablated mice (KO-/-) and a novel specific PMCA4 inhibitor, AP2 were used to study effects of PMCA4 on arterial contractility. Vascular constrictor responses to 100mM potassium & noradrenaline (1x10-9M-3x10-5M) of isolated, pressurised mesenteric arteries from male PMCA4 KO-/- and wild type, (WT+/+) mice were determined by myography. Effects of acute PMCA4 inhibition with AP2, nitric oxide synthase (NOS) inhibition with Nω-Nitro-L-arginine (LNNA) & neuronal NOS inhibition (nNOS) with Vinyl-L-Nio were also investigated. PMCA4 ablation had no effect on the magnitude of constrictions to 00mM K+ (KO-/- 53.2% ± 3.5 n=11; WT+/+ 56.3% ± 3.6 n=14) or noradrenaline (KO-/- 59.5% ± 4.7 n=11; WT+/+ 58.2% ± 2.5 n=14). PMCA4 inhibition with AP2, significantly attenuated constriction to noradrenaline in arteries from WT+/+ mice (70.6% ± 3.4 n=8 and 63.8% ± 2.6 n=10 in the absence and presence of AP2 respectively) but had no effect on KO-/- mice arteries. Inhibitory effects of AP2 were reversed in arteries by NOS inhibition with LNNA (AP2 treated 61.8% ± 4 n=8; AP2+LNNA treated 69.2% ± 1.7 n=10) and also by nNOS inhibition with Vinly-L-Nio (AP2 61.8% ± 4 n=8; AP2+Vinyl-L-Nio 75.2% ± 1.3 n=5). Therefore, PMCA4 inhibition with AP2 reduces vascular constriction by a nNOS-dependent mechanism. Ablation and acute inhibition of PMCA4 have different effects on mouse mesenteric arterial contractility.

Reactive hyperemia index and detection of endothelial dysfunction in paediatric hemato/oncology patients

P. Jehlicka, M. Huml, T. Votava, J. Kobr — 2011-12-01

Objective: The aim of our study was to evaluate endothelial dysfunction (ED) in children following treatment for acute lymphoblastic leukemia (ALL) in comparison with healthy controls (HC) and to correlate Reactive Hyperemia Index (RHI) with anthropometric and biochemical parameters.

Assessment of endothelial function and arterial stiffness in patients with genetically confirmed familial hypercholesterolemia without previous cardiovascular events

2011-12-01

Purpose: The purpose of this study was assessment of endothelial function and arterial stiffness parameters in subjects with familial and non-familial hypercholesterolemia. Methods: We studied endothelial function and arterial stiffness in 60 subjects (mean age 41.9±7.7 years): 20 patients with elevated LDL and genetically confirmed familial hypercholesterolemia; 20 patients with elevated LDL without mutations causing FH; 20 healthy controls with normal LDL. All study subjects were without previous cardiovascular events and had no symptoms of cardiovascular diseases. High-resolution ultrasound was used to determine flow-mediated dilation in the brachial artery. Echo-tracking and photoplethysmography technique were used for assessment of the arterial stiffness parameters.

The relationship between brachial artery flow-mediated dilation and shear rate in individuals with increased cardiovascular risk

2011-12-01

Brachial artery flow-mediated dilation (baFMD) is a frequently-used technique to assess endothelial function. Although shear rate (SR) is currently considered as a determinant of baFMD, a previous study in healthy humans found that the relationship between baFMD and SR was not evident in older adults. Furthermore, the relationship has not been studied in individuals with increased cardiovascular (CV) risk. The purpose of this study was to examine the relationship between FMD and estimated SR stimulus in middle-aged and older adults with increased CV risk. Data from 2 groups [37 individuals with increased CV risk (history of recent stroke or transient ischemic attack, presence of hypertension and type2 diabetes, 68.9±9.1 yrs, 6F), and 17 apparently healthy individuals (64.2±4.6 yrs, 12F)] were compared. baFMD was assessed using a 5-min forearm occlusion method. Diameter and blood velocity data obtained by a Doppler ultrasound machine were used for the calculation of baFMD and SR using semi-automated edge detection software. In the increased CV risk group, baFMD was significantly correlated with baseline SR (r=0.52), peak SR (r=0.62), and SR area under the curve until time to peak dilation (r=0.62, all p<0.05), whereas no SR indices were associated with baFMD in the healthy group. Multivariate analysis revealed that age and baseline diameter were independent determinants of baFMD in the pooled data set (R2=0.322). These findings suggest that in individuals with increased CV risk baFMD is correlated well with SR stimulus. The significance of the association between SR stimulus and baFMD in this population requires further investigation.

25-Hydroxyvitamin D may contribute to differences in arterial stiffness and endothelial function in healthy African Americans compared to European Americans

T. Dudenbostel, J.A. Alvarez, A.P. Ashraf, S.E. Judd, B.A. Gower, D.A. Calhoun — 2011-12-01

Vascular function is reportedly influenced by vitamin D and is worse in African Americans (AAs) relative to European Americans (EAs). Reasons remain unclear especially if ethnic differences in 25-hydroxyvitamin D [25(OH)D] levels mediate differences in vascular function. This prospective study investigated the relationships of serum 25(OH)D with indices of vascular function among 45 healthy, 18-50 yo AA and EA adults. The main outcomes were augmentation index (AIx75), central aortic pressure, pulse wave velocity (PWV), flow-mediated dilation (FMD), and seated and supine blood pressures. Results showed that 25(OH)D was inversely associated with AIx75, supine systolic blood pressure (SBP), central aortic SBP and central aortic diastolic blood pressure (DBP), independent of age, sex, and percent body fat (P<0.05 for all). 25(OH)D was associated with AIx75, PWV and FMD (P=0.05 to 0.08) among AAs, but not EAs (P=0.44 to 0.96). AAs had greater AIx75 (P=0.04) and PWV (P=0.07) and lower FMD (P=0.02). The relationship between age and PWV was significant in low 25(OH)D versus normal 25(OH)D status. In conclusion, 25(OH)D may have favorable effects on vascular function, particularly AAs, and lower 25(OH)D among AAs may contribute to their greater arterial stiffness and endothelial dysfunction. Furthermore, adequate vitamin D levels may attenuate age-related increases in arterial stiffness.

The patients with ischemic stroke in the posterior circulation territory have impaired endothelial function and cerebrovascular reactivity

A.Yu. Vishnyakova, O.B. Kerbikov, S.A. Svoevolin, S.E. Lelyuk, V.G. Lelyuk — 2011-12-01

The aim was to assess EF, CVR and intima-media thickness (IMT) in patients with IS in the posterior circulation territory (PCT). Methods: The study population consisted of 13 patients with IS (without atrial fibrillation) in PCT (72 hours after stroke onset). For these subjects, EF and CVR were compared against an age and gender-matched group consisting of 10 healthy individuals (control group, CG). EF was assessed using the brachial flow-mediated vasodilatation (FMD). Breath-holding test (CVR_BHT=test/baseline mean velocity) and hyperventilation (CVR_HV=baseline/test mean velocity) were used for CVR evaluation in basilar artery (using transcranial Doppler).

Endothelial function is decreased in patients with lacunar ischemic stroke and intact in patients with atherothrombotic stroke

V.G. Lelyuk, O.B. Kerbikov, E.N. Borskaya, A.Yu. Vishnyakova, A.S. Svoevolin — 2011-12-01

The aim of this study was to compare EF and cerebrovascular reactivity (CVR) in patients with LS and patients with atherothrombotic stroke (AS). Methods: The study population consisted of 10 patients with LS (21 days after stroke onset). For these subjects, EF and CVR were compared against an age and gender-matched group consisting of 10 patients with AS. The stroke subtype was classified according to TOAST criteria. EF was assessed using the brachial flow-mediated vasodilatation (FMD). Peak shear stress was used for FMD normalization. Breath-holding test (CVR_BHT=test/baseline mean velocity), hyperventilation (CVR_HV=baseline/test mean velocity) and test with nitroglycerine (CVR_NG= baseline/test mean velocity) were used for CVR evaluation in middle cerebral and basilar artery (using transcranial Doppler).

Genetic influences on the relation between exhaled nitric oxide and arterial stiffness: A twin study

2011-12-01

Objectives: Fractional exhaled nitric oxide (FENO) has an important physiological role in the airways and vessel walls. Methods: 117 adult twin pairs were recruited in Hungary, Italy and in the United States (83 monozygotic and 34 dizygotic pairs; age 48±16 years). FENO was measured by an electrochemical sensor-based device and markers of arterial stiffness (augmentation index on brachial artery, Aixbra and on aorta, Aixao; Pulse Wave Velocity on aorta, PWVao) by oscillometric method (TensioMed Arteriograph, TensioMed Ltd., Budapest). Bivariate Cholesky decomposition models were applied.

Increased aortic pulse wave velocity is associated with subclinical atherosclerosis but not with endothelial dysfunction in hypertensive patients

M.F. Neves, A.R. Cunha, J. D'El-Rei, A.K. Burlá, W. Oigman — 2011-12-01

Background: Increased vascular stiffness has been recently considered a marker of cardiovascular risk and a predictor of cardiac events Objective: To compare parameters of endothelial dysfunction and carotid atherosclerosis in hypertensive patients presenting increased vascular stiffness.

Cinacalcet may reduce arterial stiffness in patients with chronic renal disease and secondary hyperparathyroidism – Results of a small-scale, prospective, observational study

J. Bonet, B. Bayes, P. Fernandez-Crespo, M. Casals, J. Lopez-Ayerbe, R. Romero — 2011-12-01

Introduction: Arterial stiffness(AS) is one important cardiovascular risk (CR) in haemodialysis patients. Secondary hyperparathyroidism (SH) is one frequent complication in this patients and become the AS. Cinacalcet is a new drug in the treatment of SH. We proposed to do the next study.

Effect of renal nerve ablation on renal perfusion and arterial wave reflection in treatment resistant hypertension

2011-12-01

Background: Renal nerve ablation (RNA) emerged as new therapeutic approach for treatment resistant hypertension. Measurement of the renal and sympathetic activity revealed a decrease in sympathetic drive to the kidney and small resistance vessels after RNA. However, the long-term consequences on renal perfusion and arterial function e.g. vascular remodeling are unknown.

Different effect of aliskiren and ramipril on arterial stiffness and wave reflection in previously untreated essential hypertension patients

L. Ghiadoni, R.M. Bruno, G. Cartoni, A. Magagna, A. Virdis, S. Taddei — 2011-12-01

Background: Essential hypertensive patients (EH) are characterized by increased arterial stiffness. The renin-angiotensin system (RAS) activation is an important pathophysiological mechanism for arterial stiffening. Aliskiren is a novel direct renin inhibitor, whose effects on arterial elastic properties in EH are unknown. In this study we evaluated whether aliskiren, as compared to the ACE-inhibitor ramipril, can improve arterial stiffness and peripheral wave reflection in untreated mild-moderate EH, according to a double-blind parallel-group study.

Effect of antihypertensive treatment on pulse wave velocity after one year in never treated, newly diagnosed hypertensive patients and its determinants

E. Rodilla Sala, J.M. Pascual Izuel, J.A. Costa Muñoz, J. Cardona, S. Tejero — 2011-12-01

Background: Aorto-femoral pulse wave velocity (PWV) is a well established method to stratify hypertensive patients, but information about the influence of treatment on this variable is scarce.

Effect of antihypertensive treatment on pulse wave velocity after one year in patients with refractory hypertension and its determinants

E. Rodilla Sala, J.M. Pascual Izuel, J.A. Costa Muñoz, J. Cardona, S. Tejero — 2011-12-01

Background: Aorto-femoral pulse wave velocity (PWV) has been shown to be modifiable by antihypertensive treatment in newly diagnosed hypertension (HT), but little is known about the effect of treatment on longer standing, refractary HT.

Correlates of augmentation index in patients with never treated uncomplicated non-diabetic patients with essential hypertension

A. Berbari, S. Mallat, N. Daouk — 2011-12-01

Objective: Assessment of the association between augmentation index (AI75) and hemodynamic factors and target organ damage in 98 patients with: 1) prehypertension (N=56, BP=120-139 / 80-89 mmHg)- GI

Carotid stiffness and wave reflection during antihypertensive therapy with calcium antagonists: Insight from a wave intensity approach

C. Palombo, C. Morizzo, F. Rakebrandt, M. Kozakova, G. Bini, A.G. Fraser — 2011-12-01

Background: Increasing evidence emphasizes the role of central pressure augmentation in the development of hypertension-related complications, and highlights the importance of targeting arterial stiffness and wave reflection with treatment.

The L-arginine/asymmetric dimethylarginine (ADMA) ratio is improved during anti-Tumor Necrosis Factor–α therapy in patients with inflammatory arthropathies: Association with aortic stiffness

K. Angel, S.A. Provan, I. Seljeflot, T.K. Kvien, D. Atar — 2011-12-01

Background: Anti-Tumor Necrosis Factor (TNF)-α therapy seems to improve cardiovascular risk in patients with inflammatory arthropathies such as rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS). ADMA competes with L-arginine as a substrate for NOS, and the L-arginine/ADMA ratio is suggested to be important for modulation of NOS activity. Objective: To examine the effect of anti-TNF-α therapy on ADMA and L-arginine/ADMA, and the associations between ADMA, L-arginine/ADMA and aortic stiffness in patients with inflammatory arthropathies.

Comparative evaluation of vascular and metabolic effects of perindopril combination with indapamide-retard or hydrochlorothiazide in hypertensive patients

A.A. Semenkin, A.B. Zhenatov, L.A. Zhivilova, O.V. Drokina — 2011-12-01

Our aim was to compare the changes of arterial stiffness (AS), endothelial function (EF) and metabolic parameters in patients with essential hypertension on treatment with combination of perindopril with either indapamide-retard or hydrochlorothiazide. The study involved 40 patients (mean age 52,4±7,1 years) who were randomly assigned to perindopril 5-10 mg o.d. in combination with indapamide-retard (P+IR) 1.5 mg o.d. (n=20) or with hydrochlorothiazide (P+HT) 25 mg o.d. (n=20). EF determined as the change of resistance index after inhalation of 400 mcg of salbutamol, AS measured as mean stiffness index after 500 mcg of sublingual trinitroglycerin (SItng), blood lipids and glucose were evaluated at baseline and 6 months thereafter. Vascular responses were calculated from digital pulse waves registered using photoplethysmography. Dynamics of BP after 6 months did not differ significantly between groups (-19.3% versus -19,2% and -16.2% versus -14.1% for systolic and diastolic BP on P+IR and P+HT, respectively, p<0.001 for all). Changes of vascular and metabolic parameters are depicted in the table.

Stabilization or regression of atherosclerosis by lifestyle modification using motivational interviewing and carotid ultrasound

J.R.M. Blekemolen, J.D. Barth, M.M.B. Zonjee — 2011-12-01

Purpose: The preventive use of noninvasive measurement of carotid intima media thickness and plaque visualization (CIMT+P) is in the Netherlands a relatively new method to detect subclinical atherosclerosis of employees. The aim of the use of CIMT+P is to archive endurable lifestyle modification in employees without cardiovascular disease.

Effects of VEGFR-1 (FLT-1) inhibition during pregnancy on the uterine circulation of the mouse

G. Osol, E. Khankin, A. Karumanchi — 2011-12-01

Recent attention has focused on the role of soluble VEGFR-1 (sFlt-1) in the genesis of preeclampsia; less is known about the role of the non-soluble form of this receptor in the maternal uteroplacental circulation during pregnancy. To investigate this question, mice were injected with an anti-VEGFR-1 antibody (35 mg/kg i.p.) every other day beginning on day 8 (n= 9) or 12 (n=11) of gestation; vehicle-only injected mice were used as controls (n=12). All animals were killed late in pregnancy (day 19), prior to onset of parturition for determination of average pup number, resorption rate, and fetal and placental weights. Gestational vascular remodeling was evaluated by measuring the unstressed diameter and length of the main uterine artery and vein, as well as segmental artery diameter and length. Day 8 Ab injection resulted in a reduction in the average number of viable pups from 10 ± 1.2 to 3 ± 1.0 (p<0.01) and a high rate of fetal resorption (75 ± 7% vs. <5% in controls; p<0.05). Reproductive performance was also compromised in the day 12 group, although to a lesser extent. Placental and pup weights were similar throughout. Main and segmental uterine artery diameters were unchanged in either Ab group, although the diameter of the main uterine vein was reduced by 38 and 33% in both 8- and 12-day Ab-injected mice, respectively (p<0.05), Main uterine and segmental artery lengths were also significantly reduced. These results indicate that VEGFR-1 inhibition significantly compromises both reproductive performance and uterine vascular remodeling during murine pregnancy.

Instability phenomena in the mechanical behavior of the aneurysm artery

E. Diouf, M. Zidi — 2011-12-01

This study proposes a mathematical model to investigate stability of arteries. The artery is considered as a prestressed thick-walled tube subjected to dynamical pressure and made of a hyperelastic and composite material [1]. To model the mechanical contributions of the different arterial components, the here considered constitutive law of the wall takes into account the isotropic part due to the elastin-dominated matrix and the anisotropic due to the collagen fibers [2]. In this context, the purpose of this work focuses on the initial formation of aneurysms in human arteries which may be modelled as instability phenomena. For that, a perturbation technique is used on the equations of motion to highlight possible instabilities of the artery. This instability interpretation provides a theoretical approach under which different biological mechanisms leading to the risk of aneurysm formation can be assessed.

Evaluation of arterial stiffness in atherosclerotic rabbits in vivo via echotracking

C. Vayssettes-Courchay, C. Ragonnet, S. Simonet, T.J. Verbeuren, J.P. Vilaine — 2011-12-01

Objectives: We have shown that large artery stiffening, a major risk factor in cardiovascular diseases, can be evaluated in hypertensive rats by echotracking, analysing arterial compliance and also the arterial pulsatile diameter distension. We aimed to analyze similarly arterial stiffness in a model of atherosclerosis.

Elastin and collagen degradation reduces the mechanical stability of arteries

A.Y. Lee, B. Han, R. Martinez, H.C. Han — 2011-12-01

Arteries with elastin deficiency demonstrate tortuosity in human and animals, but the underlying mechanism has not been clearly elucidated. Our previous studies suggested that mechanical instability is a mechanism that leads to vessel tortuosity [1]. The objective of this study was to determine the role of extracellular matrix proteins in maintaining the mechanical stability of arteries. To this end, two groups of porcine carotid arteries were treated with elastase (8U/ml) and collagenase (2000 U/ml) respectively and tested before and after the treatments. The arteries were tested for pressurized inflation and the data were fitted with a Fung strain energy function to determine their stress-strain relationship. The critical pressures, at which the arteries became unstable and started to bend, were determined by a buckling test. The specimens were then processed for elastin staining and collagen staining and microscopy examinations. Our results demonstrated that elastase and collagenase treatment led to significant decreases in wall stiffness and critical buckling pressure of arteries. For example, the pre- and post- elastase treatment critical pressures of arteries are 19.9±5.3 kPa and 9.1±3.6 kPa, respectively, at in vivo length (n=6. p<0.05, see ). These results suggested that elastin and collagen degradation reduced the stability of arteries making them more susceptible to buckling and that mechanical buckling could initiate vessel tortuosity.

Does the aortic valves correspond to a stable anatomical landmark?

M. Hallab, A. Dahou, P. Chevalet — 2011-12-01

Purpose: In order to determine if the height of a subject could be a reliable surrogate variable to determine the pulse wave travelling distance within the aorta, we investigated the anatomical distance between the aortic valve nidus and the hyoid bone.

Is the backward reflected wave detrimental to left ventricle performance?

C.M. Park, M.Y. Henein, A.D. Hughes, A.W. Khir — 2011-12-01

The effect of the backward reflected wave (BCW) on left ventricular (LV) performance is a highly debated area. The aim of this study was to establish whether the arrival of a BCW has a detrimental effect on LV axis shortening.

Verifying the newtonian assumption for blood flow in aneurismal growth modelling

M. Nabaei, N. Fatouraee — 2011-12-01

A few number of studies have examined the effect of hemodynamic factors on the initiation and growth procedure of cerebral aneurysms. The Newtonian behaviour is assumed for blood flow in almost all of the mentioned investigations. Since the majority of intracranial aneurysms occur at bifurcations, to verify this assumption, we constructed a 3D model of the basilar artery bifurcation that includes the luminal hemodynamics and the arterial wall response within a computational fluid-structure interaction (FSI) framework. The arterial wall was assumed to be elastic and isotropic. The flow was considered steady, laminar, and incompressible. The blood flow was assumed to behave both Newtonian and no-Newtonian following Carreau model (Cho, YI, Kensey, KR, Biorheology, 28:241–262, 1991). The fully coupled fluid and structure models were solved with the finite elements package ADINA 8.5. The blood pressure and velocity and the wall shear stress (WSS), effective stress and deformation distributions were compared in two cases. The results show similar patterns except the WSS magnitudes which were under-estimated with the Newtonian assumption. This difference was evident in the low velocity regions like the apex of the bifurcation (about 20%) which is a probable position for the aneurysm formation. WSS is one of the critical hemodynamic factors affecting aneurismal initiation and development. Therefore, we believe that it is worth to consider the non-Newtonian behaviour of blood flow in order to investigate the detailed relationship between hemodynamic factors and vascular diseases, and it may affect the growth procedure of cerebral aneurysms.

Comparative investigation of mechanical characteristics of stable and unstable carotid atherosclerotic plaques

M.I. Tripoten, O.A. Pogorelova, A.N. Rogoza, T.V. Balakhonova — 2011-12-01

The prognosis of patients with carotid atherosclerosis is determined by the factor of unstable atherosclerotic plaque. Change of longitudinal strain in junction place of healthy artery wall to plaque determined by local artery elasticity and leads to instability.

Analyze of a stochastic anisotropic fibrous constitutive law effect on the human arterial pressure

A. Eddhahak-Ouni, I. Masson, F. Mohand-Kaci, M. Zidi — 2011-12-01

This research work deals with a stochastic approach using the entropy maximum principle to investigate the effect of parameters uncertainties on the arterial pressure. Motivated by a composite constitutive law with collagen fiber families [1], a set of uncertain parameters describing the mechanical behavior of the artery wall was considered. On the light of the available information, probability density functions were considered for the random variables governing the constitutive law in order to describe the dispersion of mechanical model response. Numerous realizations were performed according to the probability distributions and the corresponding arterial pressure results were compared to human non invasive clinical data recorded over a mean cardiac cycle. To prove the convergence of the probabilistic model, simulations of Monte Carlo were performed [2]. The different realizations were useful to define a reliable confidence region in which the probability to have a realization is equal to 95%. The obtained results demonstrate that the error in the estimation of the arterial pressure can reach 35% when the estimation of model parameters is subjected to an uncertainty ratio of 5%. Eventually, a sensitivity analysis was performed to discuss the influence of every uncertain parameter on the arterial pressure to identify the main parameters which contribute significantly in the constitutive law for a better understanding and characterization of the arterial wall mechanical behavior.

The influence of antihypertensive treatment on arterial stiffness and selected matrix metalloproteinases plasma activity

M.W. Rajzer, W. Wojciechowska, D. Fedak, K. Kawecka-Jaszcz — 2011-12-01

The aim of the study was to compare the effects of 5 selected drugs on arterial stiffness and matrix metalloproteinases (MMPs) plasma activity in patients with essential arterial hypertension (HT).Material and methods: 95 pts. with HT stage 1 and 2, (N=19 in each treatment group) were treated for 6 months by: quinapril 20-40 mg/d (group-1), amlodipine 5-10mg/d (group-2), hydrochlorothiazide 12,5-25mg/d (group-3), losartan 50-100 mg/d (group 4), bisoprolol 5-10 mg/d (group-5). Before and then after 1,3 and 6 months of treatment office blood pressure (BP) was measured using Omron M5-I device. Carotid femoral pulse wave velocity (PWV) was measured using 3 devices Complior®, Sphygmocor® and ArteriographTM.. Plasma concentration of (MMPs): MMP1, MMP2, MMP3, MMP9 and MMPs tissue inhibitor (TIMP1) was measured twice i.e. before and after 6 months of treatment using micro- ELISA method. Results: At the baseline no differences between groups were observed in BP, PWV and MMPs activity. ANOVA for repeated measurements revealed for all groups during treatment significant decrease in systolic BP (p<0.001), diastolic BP (p<0.001), PWV (p<0.001), MMP2 (p<0.05) and MMP3 (p<0.001) and increase of TIMP1 (p<0.001) plasma concentration. No between treatment groups differences were observed in above mentioned effects. Decrease of PWV was in significant relation to its baseline value (B= 0.498, p= 0.00041), decrease of MMP3 (B=0.211, p=0.0021 and increase of of TIMP1 (B=0.263, p= 0.0052). Conclusion:Antihypertensive treatment reduces arterial stiffness proportionally to its baseline value and independently of the used drug. The reduction of arterial stiffness depends on decrease of extracellular matrix degradation.

The effect of wall motion on the haemodynamics of Middle Cerebral Artery (MCA) aneurysm

T.S. Safavi, M. Nabaei, N. Fatouraee — 2011-12-01

External forces, accelerations and displacements, due to sudden motions of head or traumas, may affect the haemodynamics and flow patterns in a cerebral aneurysm. Despite several studies on blood flow dynamics and arterial wall mechanics in intracranial aneurysms, limited investigations considered the external forces or motion of the arterial wall. Therefore in this study, we have numerically analyzed the effects of wall movement on cerebral aneurysms with the fluid and structure interaction (FSI) theories. A 3Dimentional Model of Middle Cerebral Artery (MCA) aneurysm (geometry adopted from R. Torii et al., Int. J. Numerical Methods in Fluids, 54:995–1009, 2007) was constructed and exposed to a realistic head motion in sagital plane. Blood was considered as a homogeneous, incompressible and Newtonian fluid and arterial wall assumed to be elastic, incompressible and isotropic. The governing equations were, continuity and Navier-Stokes equations for fluid domain and equilibrium equations and Hooke's Law for arterial wall. The flow was steady and motion was applied to the arterial wall. Simulations were carried out using the commercially availed finite element software. The effect of wall motion on flow patterns and wall shear stress, strain and effective stress distributions have been discussed. The results show that arterial wall motion doesn't change the magnitude of major hemodynamic factors and wall stress and strain distributions considerably and won't lead to aneurismal rupture directly, but obviously affects the blood flow patterns in cerebral aneurysms.

Combined B-mode, Acoustic Radiation Force (ARF), and Doppler real-time imaging system for assessing cardiovascular mechanics and blood flow hemodynamics

J.R. Doherty, D.M. Dumont, D. Hyun, J.J. Dahl, G.E. Trahey — 2011-12-01

In efforts to monitor the progression of atherosclerosis using ultrasound, Acoustic Radiation Force Impulse (ARFI1) and Shear Wave Elasticity Imaging (SWEI2) have been implemented to measure the mechanical stiffness of vascular tissue while colorflow Doppler and spectral Doppler techniques have been used to monitor the associated blood flow hemodynamics.

Augmented aortic forward pressure wave amplitude contributes to increased left ventricular mass in overweight adolescents

G.L. Pierce, A. DiPietro, M. Pajaniappan, L.A. Ortiz, S. Bell, G.K. Gapuku — 2011-12-01

We hypothesized that aortic forward pressure wave amplitude, which is determined by characteristic impedance (Zc) and peak flow in the proximal aorta, contributes to increased left ventricular (LV) mass observed in overweight (OW) adolescents. Aortic pulsatile hemodynamics were measured non-invasively in sixty healthy adolescents (age 14-19 yrs; 42% male) by sequential recordings of pulse waveforms via tonometry, brachial BP, and pulsed Doppler and diameter of aortic outflow tract using 2D echocardiography. LV structure and function was assessed by 2D echo. OW adolescents (n=23; age 16.0 ± 0.3 yrs; BMI ≥85th percentile) had higher LV mass index (LVMI), brachial and carotid systolic BP and PP (all P<0.05), but not mean BP, carotid-femoral PWV or augmentation index compared with normal-weight (NW, n=37; 16.7 ± 0.3 yrs; BMI <85th percentile) (P>0.05). OW demonstrated lower resistance (Z0, 1512 ± 91 vs. 1786 ± 70 dyne x sec/cm5) and higher Zc normalized to Z0 (0.13 ± 0.01 vs. 0.11 ± 0.01) and forward wave amplitude (Pf, 48 ± 3 vs. 40 ± 2, mmHg) compared with NW (all P<0.05). Adjusting for age and sex, LVMI correlated with brachial and carotid systolic BP and PP (r=0.26-0.30), Z0 (r=-0.27), Zc normalized for Z0 (r=0.29), and Pf (r=0.32) (all P<0.05). Stepwise multiple regression revealed that BMI (β ± SE; 0.69 ± 0.19; R2=0.26) and Pf (0.23 ± 0.07; R2 change=0.11) were the best predictors of LVMI (total R2=0.37, P<0.01). These findings suggest that augmented Pf is a major hemodynamic determinant of increased LV mass with obesity in adolescents.

Inflammation and pre-atherosclerotic vascular changes in healthy 5 year old children

2011-12-01

Background: Inflammation is important in atherosclerosis development. Whether common causes of inflammation, like common infections and allergies, contribute to vascular changes already in childhood remains unknown.

Aortic stiffness indices in first-ever and recurrent ischemic stroke – A preliminary report

2011-12-01

Background: Patients with acute ischemic stroke have higher aortic stiffness estimated by carotid-femoral pulse wave velocity (CF-PWV) and central augmentation index (cAIx) than control hypertensives. Whether CF-PWV and cAIx may distinguish patients with first-ever (FES) from those with recurrent ischemic stroke (RS) is unknown.

Aortic and visceral fat inflammation detected by positron emission tomography/computed tomography (PET/CT) does not correlate with arterial stiffness in patients with a history of cardiovascular disease

M. Elkhawad, R. Wells, J. Cheriyan, J.H.F. Rudd, I.B. Wilkinson — 2011-12-01

Background: Arterial and systemic inflammation are associated with increased arterial stiffness in several patient groups. Visceral fat has been shown to contain inflammatory cells and is associated with increased cardiovascular risk. In this study we sought to investigate whether the degree of arterial and visceral fat inflammation correlated with arterial stiffness.

Abdominal aortic aneurysms exhibit greater metabolic activity detected by positron emission tomography/computed tomography (PET/CT) compared to matched controls

M. Elkhawad, J.H.F. Rudd, J.R. Boyle, J. Cheriyan, I.B. Wilkinson — 2011-12-01

Background: Chronic inflammation is a hallmark characteristic in the patho-physiology of abdominal aortic aneurysms (AAA) and atherosclerosis. These two conditions also share a number of risk factors; however it is thought that their pathophysiologies are different. In this study we sought to prospectively investigate whether there was a greater degree of inflammation in the aortas of AAA patients compared to matched controls with atherosclerosis.

Coupling of left ventricular twist mechanics and central augmentation index in healthy individuals

E.J. Stöhr, B.J. McDonnell, J. Thompson, K. Stone, J.R. Cockcroft, R. Shave — 2011-12-01

Objectives: To explore the influence of aerobic fitness (VO2 max) on the relationship between left ventricular (LV) twist and vascular augmentation index (AIx) in young healthy individuals.

24 hour ambulatory central BP measurement reveals significant variation in pulse pressure amplification between day and night

2011-12-01

Introduction: Brachial ambulatory blood pressure monitoring (ABPM) provides greater predictive value for cardiovascular events than clinic blood pressure (BP) readings. However, systolic BP varies throughout the arterial tree, such that brachial BP readings do not reliably indicate central (aortic) pressure. As yet, 24 hour ambulatory central BP, and central to peripheral pressure amplification have not been described.

The comparison of eNOS mutation 894G>T and its relationship with arterial stiffness

A. Cozma, A.V. Sitar taut, O.H. Orasan, L.M. Procopciuc, D. Pop, D.T. Zdrenghea — 2011-12-01

Acknowledgement: Grant ID 2246/2009 Background: Pulse wave velocity is a strong predictor of cardiovascular events and mortality. It is known that NO can influence arterial stiffness through vascular tone regulation. The presence of eNOS mutations can influence arterial stiffness. Purpose of the study was to investigate the relation between 894G>T mutation and arterial stiffness.

Shear strain in the common carotid arterial wall related to age?

T. Idzenga, S. Holewijn, H.H.G. Hansen, C.L. De Korte — 2011-12-01

The primary trigger for myocardial infarction and stroke is destabilization of atherosclerotic plaques. It has been hypothesized that locally increased longitudinal shear strain (LSS) facilitates the development of vulnerable plaques [1]. LSS is defined as the change of longitudinal deformation in radial direction. Ultrasound strain imaging allows local assessment of LSS [2].

Pressure-independent association between aortic stiffness and left ventricular concentric geometry

G. Schillaci, G. Pucci, L. Settimi, M. Pilati, A. Baroni, E. Mannarino — 2011-12-01

Background: Systolic blood pressure (BP) is the main pressure determinant of left ventricular (LV) mass in hypertension. It is uncertain whether arterial stiffness and central hemodynamics are related to LV mass and geometry independently of brachial, central or 24-hour BP level.

Systemic lupus erythematosus and cardiovascular events

A. Cypiene, D. Miltiniene, J. Dadoniene, A. Laucevicius — 2011-12-01

Objective. To identify the frequency and character of cardiovascular events in patients with systemic lupus erythematosus (SLE) and to examine the risk factors for their development.

B2-microglobulin, pulse pressure and metabolic alterations in patients on hemodialysis

V. Raikou, N. Tentolouris, D. Kyriaki, A. Evaggelatou, J. Boletis — 2011-12-01

Background/Aim: Pulse pressure (PP) is a result of arterial stiffness seen in dialysis patients, but may be a consequence of fluid overload. We examined the role of beta2 –microglobulin (β2 M) in PP in relation to metabolic alterations in patients on different hemodialysis (HD) modalities.

Coronary calcification in young and middle-aged men with coronary artery disease

S.G. Kozlov, T.V. Balachonova, H.A. Machmudova, M.B. Belkind — 2011-12-01

Objective: To compare the presence and extent of coronary calcification in young and middle-aged patients with new onset coronary artery disease (CAD) with matched controls without a history of CAD.

Influence of subclinical thyroid failure on arterial stiffness in women with arterial hypertension

O. Ryabtceva, Z. Blankova, T. Chazova, F. Ageev, I.A. Orlova — 2011-12-01

Background: The association between arterial stiffness increasing and mortality in patients with arterial hypertension (AH) is well recognized. There is ongoing debate whether subclinical thyroid failure may exert deleterious effects on the cardiovascular system with the consequences of increased morbidity and mortality. The OBJECTIVE of our study was to examine influence subclinical hypothyroidism (SCH) on arterial stiffness in women with arterial hypertension.

Angiotensin converting enzyme -2 (ACE-2) polymorphisms RS4646156 and RS4646174 are associated with central pulse pressure, brain natriuretic peptide and NYHA classification in patients with chronic heart failure

A. Vašků, J. Pařenica, M. Pávková-Goldbergová, P. Kala, M. Poloczek, J. Špinar — 2011-12-01

The pulse pressure (PP) is an independent predictor of cardiovascular morbidity and mortality. The PP level increases with the age and this increase is due to stiffness of large arteries. Angiotensin I converting enzyme 2 cleaves angiotensin I to angiotensin - (1-7) with vasodilatation and antiproliferative effects. In human medicine, the ACE-2 relation to the pulse pressure has not been studied yet. The aim of the study was to test possible association among phenotypes (central pulse pressure evaluated by invasive method in stable patients with well-preserved systolic function of the left ventricle, BNP as a marker of a severity of the disease and NYHA classification) and genotypes in two polymorphisms of ACE–2 gene.

Blood pressure variability is associated with aortic stiffness and Troponin-T in patients with CKD stages 3 and 4

L.A. Tomlinson, M.L. Ford, E.R. Smith, S.G. Holt, C. Rajkumar — 2011-12-01

Introduction: Clinic blood pressure predicts future cardiovascular risk but variability of systolic blood pressure (SBP) may be closely associated with adverse outcomes. Increased variability of SBP may be due to loss of buffering capacity in the aorta through increased vascular stiffness. This may be important in chronic kidney disease (CKD) where patients have accelerated aortic stiffening and high cardiovascular mortality. However, the relationship between aortic stiffness and BP variability in patients with CKD has not previously been studied.

Calcification of the thoracic aorta on chest X-ray – Associations with abdominal aortic calcification and pulse wave velocity in patients on renal replacement therapy

2011-12-01

Background: Abdominal aortic calcification (AAC) on lateral abdominal x-ray and carotid-femoral pulse wave velocity (PWV) are independent predictors of mortality and non-fatal CV events in patients on renal replacement therapy (RRT). Guidelines suggest that the presence of AAC can be used to identify patients at high risk. In this study aortic arch calcification (AoAC) on chest x-ray was correlated with the above mentioned established markers of vascular calcification.

Determinants of subclinical organ damage in paediatric kidney transplant recipients

É. Kis, O. Cseprekál, A. Kerti, T. Horváth, A.J. Szabó, M. Kollai, G.S. Reusz — 2011-12-01

Increased cardiovascular (CV) risk caused by uraemic milieu decreases after kidney transplantation (Tx), however it remains 5 fold higher than in the general population. CV mortality can be characterized by non-invasive measure of arterial stiffness (Ast). (Pulse Wave Velocity (PWV), distensibility (D), and Intima media thickness (IMT)) Clinical studies on arterial wall damage in kidney transplant children are sparse.

Different behaviour of arterial stiffness according sex and age in a population of patients in primary prevention

P. Forcada, D. Olano, S. Gonzalez, S. Obregon, C. Castelaro, C. Kotliar — 2011-12-01

Background: There is conflicting evidence about the arterial stiffening process with age. Although differences according sex have been described in the CV system (heart, emodynamics, IMT etc) little was described about arterial stiffening according sex and age simultaneously.

Common carotid artery parameters and cardiovascular risk factors in hypertensive adolescents

2011-12-01

Objective: According data of clinical studies the relationship between cardiovascular risk factors and measured common carotid artery (CCA) intima-media thickness (IMT) is a marker of preclinical atherosclerosis in adolescence. The aim of our prospective cross-sectional study was to evaluate arterial wall parameters – IMT, distensibility and stiffness of CCA and cardiovascular risk factors (systolic and diastolic blood pressure (BP), body mass index (BMI) and smoking) – in hypertensive adolescents (HA) and normotensive adolescents (NA).

Parameters of local and systemic arterial stiffness in patients with arterial hypertension and moderately marked carotid atherosclerosis with and without diabetes

2011-12-01

Aim: To evaluate parameters of local and systemic arterial stiffness in patients with arterial hypertension (AH) and moderately marked carotid atherosclerosis (CA) with/without diabetes.

Long-term prognosis of coronary artery chronic total occlusions revascularization

M.A. Maslennikov, Y.A. Karpov, O.V. Cherkavskaya, B.A. Rudenko, A.P. Savchenko — 2011-12-01

Background: The clinical benefit of chronic total occlusions (CTO) recanalisation is still being discussed. The aim of our study is to analyse long-term clinical results of CTO recanalisation drug-eluting stent implantation.

Arterial stiffness and intima-media thickness as early markers of vascular alterations in patients with metabolic syndrome

N. Spasova, E. Kinova, D. Somleva, T. Kourteva, A. Goudev — 2011-12-01

Background: Metabolic syndrome (MS) is associated with early abnormalities in arterial wall and an increased risk of cardiovascular diseases. High arterial stiffness and intima-media thickness (IMT) are markers of vascular aging and subclinical organ damage.

Rheumatoid arthritis and cardiovascular events

S. Stropuviene, S. Aidietiene, A. Cypiene, R. Rugiene, A. Laucevicius — 2011-12-01

Objective: Rheumatoid arthritis (RA) is inflammatory autoimmune disease, which is associated with increased cardiovascular mortality. In this study clinical data were analysed to look for a risk factors for the development of cardiovascular events in RA patients.

Determinants of arterial stiffness in young individuals at low cardiovascular risk: The role of autonomic nervous system

2011-12-01

Our aim was to study the influence of autonomic nervous system and other factors on arterial stiffness in young individuals at low cardiovascular risk. The study involved 136 healthy individuals (mean age 23.5±6.7 years, 89 men and 47 women). The examination included: cardiovascular risk factors screening, heart rate variability (HRV), vascular stiffness, and endothelial function evaluation. Stiffness index was measured at baseline (SIbl) and after 500 mcg of sublingual trinitroglycerin (SItng). Endothelial function was determined as the change of resistance index after inhalation of 400 mcg of salbutamol (EF). Vascular responses were calculated from digital pulse waves (DPW) registered using photoplethysmography. Vascular parameters did not differ between men and women. On multivariate analysis age and diastolic blood pressure were the only determinants of SIbl among the conventional risk factors (R=0.37, R2=0.14, p<0.001). Age, systolic blood pressure, and EF were independent predictors of SItng (R=0.57, R2=0.33, p<0.001). Among HRV parameters added to the above models low parasympathetic activity and elevated sympathetic activity evaluated by pNN50 and low frequency waves spectrum (LF), respectively, were independent predictors of higher levels of SIbl (p<0.00001 for each parameter). The model explained nearly 40% of SIbl variability (R=0.62, R2=0.38, p<0.00001). Only pNN50 was independently related to SItng in multivariate model (p<0,01) marginally increasing its predictive value (R=0.64, R2=0.41, p<0.00001). Thus, autonomic nervous system significantly affected baseline arterial stiffness evaluated by DPW analysis in young individuals. Whereas SItng is minimally influenced only by parasympathetic tone and more precisely reflects cardiovascular risk factors effects on arterial wall.

Cardiovascular risk in the view of individual risk factors in patients with more than 1 risk factor present

2011-12-01

Context and objective: It is known that patients, with a diagnosis of metabolic syndrome (MetS) having three or more cardiometabolic risk factors (CmRF) are associated with an increased cardiovascular risk. The study aimed at evaluating the increase of the risk depending on a number of individual CmRF while evaluating early subclinical atherosclerosis indicators measuring arterial markers, such as PWV and Aix, as well as eGFR.

The comparison of eNOS mutation T786C and its relationship with arterial stiffness

2011-12-01

Acknowledgement Grant ID_2246/2009. Background: Arterial stiffness represents a strong predictor of the cardiovascular events and mortality, but seems to be influenced by eNOS mutations (responsible for alteration of NO release).

Heritability of central blood pressure and pulse pressure – A twin study

2011-12-01

Objective: Central blood pressure (SBPao), peripheral and aortic pulse pressure (PP, PPao) are powerful predictor of cardiovascular events. No comprehensive twin study has investigated their heritabilities.

Clinical and vascular parameters correlated with augmentation pressure in a Brazilian hypertensive population

2011-12-01

Background: Augmentation pressure (AP) has been considered an absolute index that represents vascular stiffness. Objective: To evaluate clinical and vascular parameters in a Brazilian population presenting hypertension and increased augmentation pressure.

Measuring aortic distensibility with CMR using central pressures estimated in the magnet: Comparison with carotid and peripheral pressures

2011-12-01

Objective: Evaluate the feasibility of local aortic distensibility measurement using central pressure estimation in the magnet, simultaneous to aortic imaging with cardiovascular magnetic resonance (CMR).

Variations of wave reflection indexes induced by acute blood pressure changes at different arm heights

G. Pucci, B. Gavish, F. Battista, L. Settimi, E. Mannarino, G. Schillaci — 2011-12-01

Acute blood pressure (BP) changes might influence augmentation index (AIx), an integrated dimensionless measure of reflected wave timing and amplitude. In 30 healthy subjects (49±16 years, 43% men), supine brachial BP and radial-artery waveform (applanation tonometry, SphygmoCor) were obtained with the right arm supported in 3 different positions: at the heart level (0°), raised by 30° (+30°), and lowered by 30° (-30°). BP and tonometric measures were also obtained on the contralateral arm, which was held at the heart level during the examination.

Validation of a brachial cuff-based method for assessing central blood pressure at rest and during light exercise

L.M. Day, D.M. Nicholson-Thomas, K.M. Maki-Petaja, C.M. McEniery, I.B. Wilkinson — 2011-12-01

Background: Central blood pressure (BP) may be more predictive of cardiovascular events than brachial BP. A cuff-based ambulatory central BP monitor is now available; the aim of this study was to compare values of central BP between this device and the SphygmoCor device.

How much does pressure wave reflection contribute to augmentation index?

A. Guilcher, S. Brett, B. Clapp, P. Chowienczyk — 2011-12-01

Background: Aortic pulse pressure can be partitioned into the height of the first systolic shoulder (P1) and augmentation pressure AP. P1 is thought to be determined by an outgoing pressure wave generated by ventricular contraction and AP by a backward wave “reflected” from the distal circulation. Augmentation index (AIx = AP / cPP) is commonly used to quantify wave reflection. Nitroglycerin (NTG) has a powerful effect to reduce AIx which has been attributed to a reduction in wave reflection. The objectives of this study were to examine the contribution of forward and backward waves to AIx at rest and after administration of NTG.

Ambulatory arterial stiffness index: another ambiguous stiffness index?

2011-12-01

Introduction: The Ambulatory Arterial Stiffness Index (AASI), derived from ambulatory blood pressure (ABPM) recordings, has been proposed as a surrogate marker of arterial stiffness. However, there is controversy to which extent it reflects stiffness or is affected by other parameters. Using a computer model of the arterial circulation, the relative importance of the different determinants of the AASI was explored.

Comparison of simultaneous invasive central arterial pressure measurements with non-invasive arterial pressure estimates by suprasystolic oscillometry using Pulsecor R6.5

A. Lin, A. Lowe, K. Sidhu, W. Harrison, P. Ruygrok, R. Stewart — 2011-12-01

Background: Many devices estimate central aortic blood pressure (BP) from non-invasive measurements. Most need calibration using separately measured BP, which introduces unquantified inaccuracies. The Pulsecor R6.5 device estimates central BP using a suprasystolic brachial cuff and built-in oscillometric BP unit in approximately 60 seconds. We compared central BP estimated using the Pulsecor device and those obtained by catheter during coronary angiography.

Comparison of two radiofraquency-based systems for assessment of local carotid stiffness

2011-12-01

Objective: two ultrasound systems (QAS, Esaote; and E-Track, Aloka) provide radio-frequency (RF)-based tracking of carotid wall, allowing real-time determination of vessel diameter, distension, and stiffness (CS). Measurement is performed in a single line by E-Track and in 16 equidistant lines by QAS.

Systolic hypertension mechanisms: Effect of global and local proximal aorta stiffening on pulse pressure

P. Reymond, O. Vardoulis, N. Westerhof, N. Stergiopulos — 2011-12-01

Decrease in arterial compliance leads to an increased pulse pressure. Pressure waveform is the sum of a forward and a reflected wave, which are altered when the arterial system stiffens. Two mechanisms have been proposed in the literature to explain systolic hypertension upon arterial stiffening. One is based on the augmentation and earlier arrival of reflected waves. The second is based on the augmentation of the forward wave due to increased characteristic impedance of the ascending aorta.

Pulse pressure amplification, pressure waveform calibration and target organ damage

2011-12-01

Background: Obtaining pulse pressure non-invasively from applanation tonometry requires the calibration of pressure waveform with brachial systolic and diastolic blood pressure. In literature, several calibration methodologies are applied and clinical studies do not agree about the predictive value of central hemodynamic parameters.

Two new indices for a more accurate assessment of the local aortic stiffness

2011-12-01

Purpose: Recently, the local aortic stiffness (AoStiff) can be evaluated using a non-invasive bioelectrical impedance (BI) technique. Herein, AoStiff is estimated from the measurement of two new BI variables: 1) The local aortic flow resistance (AoRes) exerted by the drag forces onto the flow 2) The local aortic wall distensibility (AoDist). We propose to compare these two indices with the reference pulse wave velocity (PWV) measurement and the direct assessment of the aortic drag forces (DF) and distensibility (DS) obtained by the magnetic resonance imaging technique (MRI).

The retrograde flow a novel parameter of aortic stiffness

2011-12-01

Aim: The aim of this prospective study was, to quantifies parameters of the retrograde flow (volume, flow rate) using magnetic resonance phase shift velocity and to study there relationships with aortic stiffness parameters calculated using both MRI and tonometry and waves reflections parameters.

Adjustment for blood pressure when measuring pulse wave velocity in newly diagnosed untreated hypertensive patients

C. Strandhave, M. Svensson, K. Holdensen, C.M. Skov, H. Krarup, J.H. Christensen — 2011-12-01

Pulse wave velocity (PWV) is a valid and well-documented predictor of cardiovascular risk in hypertensive patients. It is essential to adjust for potential confounders, and especially age and blood pressure (BP) modulate the level of PWV. Both systolic BP and mean arterial pressure (MAP) have been used when adjusting in statistical models. However, in recent years MAP has been favoured for BP adjustment.

Accuracy of oscillometric determination of the ankle-brachial index as screening method for peripheral artery disease

2011-12-01

Aim: The ankle brachial index (ABI) is a non-invasive measure for the assessment of peripheral artery disease (PAD). Currently, its use is not sufficiently implemented in general practice, because it is time-consuming. An automated test may facilitate screening for PAD. In this study we assessed the accuracy and reliability of oscillometric ABI determination compared with Doppler.

Atherosclerotic plaque evaluation based on the results of ultrasound duplex scanning (DS), multispectral resonance imaging (MRI), multispiral computed tomography (MSCT) and histochemical analysis in asymptomatic patients with marked carotid atherosclerosis

L.R. Tokloueva, T.V. Balakhonova, E.Y.U. Strazden, M.M. Loukyanov, S. Boytsov — 2011-12-01

Aim: To evaluate morphological and functional characteristics of an atherosclerotic plaque (ASP) in patients with marked carotid atherosclerosis. Materials and methods: Forty patients (25 males, age 68.9±6.6 years) with marked carotid atherosclerosis (stenosis ≥ 70%, based on ultrasound DS, MSCT and MRI data) were examined before carotid endarterectomy (16 cases with history of cerebral stroke, CS – Group 1; 24 cases without – Group2). All the patients were asymptomatic (no acute cerebrovascular events in the last 6 months). Histochemical examination of the excised carotid ASP was performed in 21 cases (9 cases in Group 1 and 12 cases in Group 2).

Systolic ambulatory blood pressure is more closely related to left ventricular hypertrophy than central aortic and brachial blood pressure in never treated hypertensive patients

2011-12-01

Background: Our purpose was to assess the relationship between left ventricular mass (LVM) and three different ways to measure blood pressure in hypertensive patients. Methods: Cross-sectional study that included non-diabetic, untreated hypertensive patients. Central aortic pressure (CAP), derived from pulse wave analysis (SphygmoCor-System), office brachial blood pressure (oBBP) and ambulatory 24-hour blood pressure (ABP) were obtained. LVM was determined by standard echocardiography (cut-off values for left ventricular hypertrophy (LVH) were 125 g/m2 for men and 110 g/m2 for women).

Comparison of the central pressure measured with a brachial cuff and invasively measured aortic pressure

O. Korolkova, A. Lowe, J.E. Davies, A.D. Hughes, K.H. Parker, J.H. Siggers — 2011-12-01

Central aortic pressure is a better predictor for cardiovascular events than brachial pressure1. There are a number of devices on the market that find a continuous measurement of pressure in the arm, and from it estimate the central aortic pressure2. In this study we focus on one such device, the PulseCor 6.5 Monitor (PulseCor, Auckland, New Zealand) 3. We compare its output (central aortic pressure waveforms) with an ensemble average of the aortic pressure waveforms measured invasively using a pressure catheter (ComboWire XT GuideWire, Volcano Corporation, Belgium). The results show that the central aortic pressure waveforms have a qualitatively and quantitatively similar shape to the invasively measured waveforms (R=0.9505) (a typical result is shown in figure). The average differences in the systolic and diastolic readings of the device with the invasive measurements are 6.75 mmHg with range [-13.09, 32.0] and 18.15 mmHg with range [-8.45, 86.38], respectively (N=8). We conclude that although the non-invasively measured systolic and diastolic pressures do not match exactly to the invasive measured ones, the waveforms of both measurements are similar.

Estimation of central systolic blood pressure from arm cuff pressure: Comparison with the sphygmocor system

S. Brett, A. Guilcher, B. Clapp, P. Chowienczyk — 2011-12-01

Objective: Central systolic blood pressure (cSBP) is usually estimated by application of a transfer function (TF) to a peripheral arterial waveform. These waveforms are usually calibrated by using either mean (MAP) and diastolic (DBP) blood pressure or systolic blood pressure (SBP) and DBP obtained from an arm cuff. The aim of the present study was to determine whether cSBP derived from upper arm cuff pressure is as accurate as that obtained from radial tonometry.

Ankle-brachial index and inflammation in relation to blood pressure classification: Ups and downs

2011-12-01

Background: Hypertension is associated with ankle-brachial index (ABI) and C-reactive protein (CRP), which are both predictors of cardiovascular risk. We investigated the differences in ABI and inflammation between the subgroups of the blood pressure (BP) classification (optimal to grade III hypertension), which was proposed by the European 2007 guidelines for the management of hypertension.

Measurement of pulse wave velocity in healthy youngsters – Reference values and comparison of three devices

2011-12-01

Carotid-femoral pulse wave velocity (cfPWV) is an established method for characterizing aortic stiffness. Normal PWV values for the paediatric population derived from large data collection have yet to be available.

Assessment of mechanical properties of carotid plaques in patients with acute ischemic stroke (AIS) using velocity vector imaging (VVI)

S.A. Voynov, O.B. Kerbikov, D.A. Golovin, V.G. Lelyuk — 2011-12-01

VVI allows to assess multi-dimensional regional mechanics of carotid wall. Objective: to investigate the mechanical properties of carotid plaques.

Time domain analysis of the arterial pulse in clinical medicine

M.F. O'Rourke — 2011-12-01

Analysis of the arterial pulse in clinical medicine is based on palpation and interpretation of the radial pulse over millennia, on invasive measurement of pressure and flow waves in experimental animals over the past century, and on analysis of waveforms in the frequency domain, together with computerized modelling over the past 50 years. Interpretation of the arterial pulse in the radial and other arteries now approaches the same acceptance as the electrocardiogram, and has the potential for similar clinical value.