Artery Research - Articles in Press

Relationship between 24 h ambulatory central blood pressure and left ventricular mass – Rationale and design of a prospective multicenter study - Corrected Proof

2012-01-24

Abstract: The prognostic superiority of ambulatory over clinic blood pressure has been repeatedly proven. However, due to the mechanical properties of the arterial system, systolic and pulse pressures are higher in the brachial artery than in the ascending aorta. It seems logical that central pressures are more relevant to cardiovascular disease than peripheral (brachial) pressures, and indeed, using clinic blood pressures, it has been shown that central systolic and pulse pressures are more closely associated with hypertensive end-organ damage than their brachial counterparts. Moreover, antihypertensive drugs can have differential effects on central versus brachial blood pressures. All these effects have been described on the basis of clinic blood pressure measurements. Recent advances in technology allow the estimation of central systolic blood pressure from brachial pulse waves recorded with a regular brachial oscillometric blood-pressure cuff, using a transfer-function like algorithm (ARCSolver). This method has been invasively validated and allows the recording of 24 h ambulatory central blood pressure profiles. Our multicenter study now aims for the first time to investigate the relationship between central ambulatory blood pressure monitoring and hypertensive end-organ damage (left ventricular mass) in untreated adults.

Increased aortic wave reflection and longitudinal regional diastolic dysfunction in patients with left ventricular hypertrophy - Corrected Proof

2012-01-24

Abstract: Objectives: Increased arterial stiffness is associated with the progression of left ventricular hypertrophy (LVH); however, the endocardial layer (End) contracts more than the epicardial layer (Epi), and it is unclear whether increased arterial stiffness affects regional wall deformation in both the End and Epi in LVH.Methods: We performed echocardiography and measured the radial augmentation index (rAIx) in 41 patients with LVH. We evaluated the longitudinal strain, and early diastolic strain rate (SRdia) (measures of regional wall deformation) in both End and Epi in addition to measures of global diastolic function. The ratios of End strain to Epi strain (End/Epi strain) and End SRdia to Epi SRdia (End/Epi SRdia) were also calculated.Results: All of the patients had a decreased LV diastolic function (E/e′>8) and preserved ejection fraction (>45%). The rAIx was slightly related to the End/Epi SRdia (r=0.29, P=0.063); the relationship of rAIx to End/Epi SRdia (beta=0.52, P=0.034) was significant after adjustment for potential confounding factors. The rAIx at heart rate 75 beats per minute (rAIx@HR75) was significantly related to End/Epi SRdia (r=0.36, P=0.023); the relationship of rAIx@HR75 to End/Epi SRdia remained significant even after the adjustment (P=0.032). The relationships of rAIx@HR75 to End/Epi strain did not reach the level of statistical significance (r=0.30, P=0.06) in this study.Conclusion: Increased rAIx, a measure of aortic wave reflection, may be associated with a regional diastolic function in the ratio of endocardial to epicardial layer of the left ventricular wall in patients with left ventricular hypertrophy.

A comparison of SphygmoCor and Vicorder devices for measuring aortic pulse wave velocity in pregnancy - Corrected Proof

T.R. Everett, A. Mahendru, C.M. McEniery, C.C. Lees, I.B. Wilkinson — 2012-01-24

Abstract: Background: Aortic pulse wave velocity (aPWV) has been found to be increased in preeclampsia when compared to normal pregnancy. Preeclampsia is associated with increased risk of later cardiovascular disease and, as such, study of the aortic stiffness in pregnancy, and its hypertensive disorders, is important to the understanding the underlying vascular changes. We compared two different techniques to measure aPWV in the mid-trimester of pregnancy.Methods: 58 women were recruited from the obstetric ultrasound clinic, mean (±SD) age 33 (±6) years and gestation 27 (±1) weeks. Aortic PWV was measured using SphygmoCor and Vicorder devices.Results: We found that both devices provided similar aPWV values with no significant difference between devices: mean difference (±SD), 0.1 (±0.9)m/s, p = 0.4. We found good correlation between devices (r = 0.6, p < 0.001). Good intra-observer variability was observed for both SphygmoCor and Vicorder devices, coefficients of variation 5.69% and 2.67%, respectively.Conclusions: The SphygmoCor and Vicorder devices produce similar readings for aPWV in the second trimester of pregnancy, with good intra-observer variability. Due to its simpler technique the Vicorder device may be more suited to the clinical setting, particularly in advanced pregnancy or obesity.

Differences in pulse pressure day variability between the brachial artery and the aorta in healthy subjects - Corrected Proof

2011-12-23

Abstract: Objectives: To search for: (i) potential differences in the within-subject pulse pressure (PP) day time variability between the brachial artery and aorta; (ii) the presence of substantial day time variation in the aortic-to-brachial (AtB) PP disparity.Background: Brachial blood pressure (BP) variability is a risk factor, but also a source of inaccuracy for the assessment of BP-related cardiovascular risk. PP differs substantially in simultaneous measurements at the brachial artery and the aorta; this is of clinical importance regarding accurate cardiovascular risk assessment and reduction strategies. Whether the brachial and the aortic PP time variability is similar, and whether the AtB PP disparity varies during the day is not known.Methods: In 13 healthy volunteers hourly assessment of brachial and aortic PP was performed (8:00–19:00) under controlled conditions at home.Results: Aortic PP day variability was consistently and significantly lower than brachial PP (assessed by: standard deviation, variance and time rate variation index, p < 0.05 for all). Individual AtB PP difference (brachial – aortic PP, mmHg) varied substantially within all the 13 subjects; a significant variation during the day in the AtB PP amplification (defined as brachial/aortic PP) was evident (p = 0.006).Conclusions: By taking into account both time and arterial space, substantial physiological differences in PP variability between the brachial artery and the aorta were observed. These novel findings suggest that non-invasive 24-h aortic ambulatory BP monitoring is warranted in order to significantly improve CV risk assessment and reduction strategies. This possibility must be tested in future clinical studies.

Central haemodynamics reveal significant potential for prevention in Black hypertensive patients born and living in sub-Saharan Africa - Corrected Proof

2011-12-15

Abstract: Background: Few studies assessed arterial stiffness in Black hypertensive patients born and living in sub-Saharan Africa, where cardiovascular disease reaches epidemic proportions.Methods: The Newer versus Older Antihypertensive Agents in African Hypertensive Patients (NOAAH) trial is currently recruiting native African patients to compare the efficacy of various antihypertensive drugs given once daily as single-pill combinations. Two centres engaged in pulse wave analysis and measured carotid–femoral pulse wave velocity (PWV). Statistical methods included single and multiple linear regressions.Results: Of 172 patients screened, 116 entered the ancillary study on central haemodynamics (51.3% women; mean age 52.7 years; untreated blood pressure 147.6/87.1mmHg). The augmentation indexes were higher (p<0.0001) in women than men, both peripherally (pAI, 11.1 vs. −10.6%) and centrally (cAI, 39.0 vs. 28.0%). PWV (8.91m/s) and central pulse pressure (cPP, 48.7mmHg) were similar (p>0.844) in both sexes. pAI and cAI increased with female sex and mean arterial pressure, but decreased with heart rate and body mass index. cPP increased with age and mean arterial pressure. PWV increased with age and mean arterial pressure. Patients with measurements above the age-specific thresholds determined in healthy Black South Africans amounted to 0 for cAI, 1 (1.2%) for cPP, and 11 (18.3%) for PWV.Conclusion: NOAAH patients have measures of arterial stiffness similar to those of a healthy Black reference population with determinants as reported in the literature. Our observations highlight the potential for the prevention of irreversible arterial damage by timely treating sub-Saharan hypertensive patients to target blood pressure levels.

Relationship between the aortic valves and an anatomical landmark using chest CT scan - Corrected Proof

Magid Hallab, Pascal Chevalet, Amine Dahou, Gilles Berrut — 2011-10-05

Abstract: 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.Methods: Using 28 patient’s chest CT-scans. From Multiplan reconstructed oblique cuts we measured 1) the length of the aortic arch from the aortic valve (AV) to the intercept of a horizontal line passing through the aortic valves and crossing the descending aorta at mark HD (see figure), and 2) the distance between the HD mark to the Hyoid Bone (HB).Results: There was a correlation between the AV-HD distance and the HD-HB distance (non-parametric r = 0.66, p < 0.0001) and the AV-HD distance were positively correlated to the height of the subjects (r = 0.60, p < 0.002).Conclusions: 1- The AV-HD distance projects to a constant anatomical landmark (i.e. the hyoid bone) 2- The size of this arterial segment is significantly correlated to the height of the subjects. These preliminary results could be useful for a more accurate determination of the pulse wave velocity.

Central and peripheral pulse wave velocities are associated with ankle–brachial pressure index - Corrected Proof

2011-09-12

Abstract: Background: Central Pulse Wave Velocity (PWV) is considered to be the gold standard measurement of arterial stiffness. In healthy subjects, cardiovascular risk factors such as age, hypertension, diabetes and end-stage renal disease are associated with increased central (Carotid–Femoral) and peripheral (Femoral–Ankle) PWV. However, little is known about PWV in patients with peripheral arterial disease and pathological Ankle–Brachial Index (ABI). The aim of this study was to study central and peripheral PWV in a population with various degree of peripheral arterial disease.Methods: Central and peripheral PWV were measured in sixty-two hospitalized patients. Half were admitted for symptomatic peripheral vascular disease and the remainder for cardiac or carotid disease. The population was classified on basis of the Framingham-derived risk score for claudicants and on the ABI. For all patients, PWV was assessed on electrocardiogram-ultrasonographic images acquired at the four following sites: carotid, radial, femoral and tibial arteries.Results: Carotid–Femoral PWV increased significantly with the Framingham-derived global risk score (p < 0.0001) but Femoral–Ankle PWV did not. With respect to the Ankle–Brachial Index, Carotid–Femoral and Femoral–Ankle PWV significantly increased (p = 0.05 and p = 0.02 respectively) with the severity of peripheral arterial scoring.Conclusions: These results confirm that central PWV is the best indicator of general atherosclerosis, even in the presence of peripheral arterial disease. Both central and peripheral PWV can be considered as indicators of the severity of peripheral vascular disease.

Hepatic arterial changes following iodized oil chemoembolization of hepatocellular carcinoma: Incidence and technical consequence - Corrected Proof

2011-09-07

Abstract: Objective: To describe the nature, incidence, and therapeutic consequence of hepatic arterial changes seen following transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).Methods: In this retrospective study, 46 patients with HCC underwent ≥ 2 TACE treatment sessions between 2004 and 2010. All patients had hepatic angiography on days of treatment. Sequential angiographic studies were reviewed to assess for abnormalities in appearance of the hepatic vasculature. Angiographic abnormalities were graded in a binary fashion: present or absent. When present, abnormalities and effect on drug delivery were recorded.Results: 123 (mean 2.7, range 2–5) successful lobar (n = 34), segmental (n = 88), or superselective (n = 1) TACE procedures were performed in 46 patients (M:F = 36:10, mean age 59 years). TACE was performed using 1:1 chemotherapy to iodized oil mixture without (n = 102) or with (n = 21) particle embolization. An abnormal angiographic appearance was identified in 21/46 (38%) patients and in 23/123 (19%) procedures, with first appearance after mean 1.5 (range 1–3) TACE sessions and mean 176 (range 27–509) days after initial TACE. Abnormalities included new vessel attenuation or stenosis (n = 10, 43%), slow flow (n = 2, 9%), and new vascular occlusions (n = 11, 48%). These vascular changes did not result in inability to perform repeat TACE in 16/16 (100%) cases where vascular changes were present and TACE was repeated to the same liver lobe.Conclusion: While the hepatic vasculature is altered in many patients undergoing TACE, arterial abnormalities did not preclude therapy.Further investigation is warranted.

Adiponectin negatively correlated with carotid arterial structure in the leptin-resistant Zucker diabetic fatty rat - Corrected Proof

Emmanuel Cosson, Paul Valensi, André Bado, Hubert Dabiré — 2011-08-22

Abstract: Background: Despite adipocytokines are implicated in arterial hemodynamic and stiffness, their effects on arterial histomorphometry remain poorly explored. The aim of the present study was to evaluate, in Zucker Diabetic Fatty (ZDF) rats, a model of type 2 diabetes with leptin resistance, carotid arterial structural changes and their determinants, with special focus on adiponectin and leptin.Methods: Proximal aortic blood pressure (BP) was measured in conscious ZDF rats (n = 6–8) and their Lean controls (n = 6–8) at 6, 12 and 24 weeks. The contralateral carotid was harvested and fixed at the mean BP for histomorphometric quantification.Results: Mean BP was similar in both strains and increased with age (p < 0.001). Medial thickness, luminal cross-sectional area (LCSA), medial cross-sectional area (MCSA) and wall stress (WS) increased with age (p < 0.001). LCSA and WS were higher in Lean than in ZDF rats (p < 0.001 for both). Leptin levels were higher in ZDF than in Lean rats (p < 0.001) but remained unchanged during development in ZDF rats. Adiponectin levels decreased with age in ZDF rats (p < 0.001) but remained unchanged in Lean rats. In all rats, adiponectin negatively correlated with medial thickness (r = −0.50, p < 0.01), LCSA (r = −0.64, p < 0.001), MCSA (r = −0.59, p < 0.001) and WS (r = −0.43, p < 0.05). These correlations were significant (p < 0.001) in ZDF rats considered separately (r = −0.73, r = −0.87, r = −0.83 and r = −0.79, respectively) but not in Lean rats; independently of mean BP and age after stepwise regression analyses.Conclusion: These associations suggest a protective role for adiponectin against arterial wall thickening and wall stress. However for causal relation, further investigation is needed.

The association between aortic regurgitation and increased arterial wave reflection - Corrected Proof

2011-08-12

Abstract: Background: Chronic Aortic Regurgitation (AR) increases left ventricular preload and afterload, which may enhance arterial wave reflection. The effects of AR on noninvasive measures of arterial wave reflection and central aortic pressure are unknown.Methods: To determine the relation between AR and wave reflection, we prospectively studied 86 subjects with AR and 50 controls referred for echocardiography. Peripheral (P) blood pressures (BP) were measured using an automated sphygmomanometer. Central aortic systolic (CS) BP, central pulse pressure (CPP), central augmented pressure (AP), heart rate corrected augmentation index (AI75), AI, reflected wave systolic duration (∆Tr) and round trip travel time (Tr) were derived from the radial artery waveform obtained by applanation tonometry (Sphygmocor®, Atcor Medical). Pulse pressure amplification (PPA) was calculated as peripheral PP/central PP. There were 50 controls, 50 with mild, 25 with moderate, and 11 subjects with severe AR. Clinical characteristics were similar among the groups.Results: AP, AI75, and CPP increased in a stepwise manner with increasing AR severity. On analysis of variance adjusted for age, gender, height, weight, mean peripheral BP, ejection fraction, and medication classes, AR severity was independently associated with increased AI75 (p<0.001), AP (p<0.001), CSBP (p=0.04). PPA decreased in a stepwise manner with increasing AR severity (p=0.001). Tr decreased and ∆Tr increased.Conclusions: AR is associated with increased amplitude and duration and earlier onset of the reflected pressure wave, which suggests arterial wave reflection to be a potentially important consideration in patients with AR.

Moderated Poster Presentation - Corrected Proof

2009-11-02