Showing papers by "Stéphane Laurent published in 2006"

Expert consensus document on arterial stiffness: methodological issues and clinical applications

Abstract: In recent years, great emphasis has been placed on the role of arterial stiffness in the development of cardiovascular diseases. Indeed, the assessment of arterial stiffness is increasingly used in the clinical assessment of patients. Although several papers have previously addressed the methodological issues concerning the various indices of arterial stiffness currently available, and their clinical applications, clinicians and researchers still report difficulties in selecting the most appropriate methodology for their specific use. This paper summarizes the proceedings of several meetings of the European Network for Non-invasive Investigation of Large Arteries and is aimed at providing an updated and practical overview of the most relevant methodological aspects and clinical applications in this area.

Expert consensus document on arterial stiffness : methodological issues and clinical applications. Commentary

Abstract: In recent years, great emphasis has been placed on the role of arterial stiffness in the development of cardiovascular diseases. Indeed, the assessment of arterial stiffness is increasingly used in the clinical assessment of patients. Although several papers have previously addressed the methodological issues concerning the various indices of arterial stiffness currently available, and their clinical applications, clinicians and researchers still report difficulties in selecting the most appropriate methodology for their specific use. This paper summarizes the proceedings of several meetings of the European Network for Non-invasive Investigation of Large Arteries and is aimed at providing an updated and practical overview of the most relevant methodological aspects and clinical applications in this area.

Carotid and Aortic Stiffness: Determinants of Discrepancies

Abstract: Several studies have shown that aortic stiffness was an independent predictor for cardiovascular events. However, data are less consistent concerning carotid stiffness. We analyzed the determinants of the discrepancies between aortic and carotid stiffness in different populations with contrasting cardiovascular risk factors: 94 healthy normotensives (NT), 243 nondiabetic hypertensives (HT), and 126 patients with hypertension and type 2 diabetes (T2D). Aortic stiffness was measured with carotid-femoral pulse wave velocity. Common carotid stiffness was determined from the relative stroke change in diameter (measured with a high-resolution echotracking system) and carotid pulse pressure (measured with applanation tonometry) and was expressed in the same dimensions as pulse wave velocity (m/s). We identified the various factors explaining the discrepancies between aortic and carotid stiffness by multivariate analysis of the residuals of the correlation between aortic and carotid stiffness. The strength of the correlation between aortic and carotid stiffness became weaker as the number of cardiovascular risk factors increased (NT, r2=0.41; HT, r2=0.16; and T2D, r2=0.11), whereas we observed the opposite for the discrepancies (residuals) between aortic and carotid stiffness, of which an increasing part was explained (11% in NT, 22% in HT, and 45% in T2D) primarily by aging. In conclusion, although carotid-femoral pulse wave velocity and carotid stiffness provided similar information on the impact of aging on large artery stiffness in normal subjects, this was not the case for high blood pressure and/or diabetes. In these cases, the aorta stiffened more than the carotid artery with age and other cardiovascular risk factors.

Brachial pressure-independent reduction in carotid stiffness after long-term angiotensin-converting enzyme inhibition in diabetic hypertensives.

Abstract: Hypertension and diabetes are associated with an increased arterial stiffness. A direct blood pressure–independent effect of angiotensin-converting enzyme inhibitors on arterial stiffness has never...

Surrogate Measures of Arterial Stiffness: Do They Have Additive Predictive Value or Are They Only Surrogates of a Surrogate?

Abstract: Recent epidemiological studies have shown that arterial stiffness, measured through carotid-femoral pulse wave velocity (PWV), has an independent predictive value for cardiovascular (CV) events in several populations, including patients with uncomplicated essential hypertension1,2 and type 2 diabetes.3 Arterial stiffness is thus an intermediate end point for CV events, predicting CV events independently of and beyond peripheral pulse pressure (PP). Peripheral PP, central PP, and augmentation index, which provide additional information on wave reflection, are considered “surrogates” of arterial stiffness, because their pathophysiological meaning is clearly different.4–6 Central PP and augmentation index are dependent on the speed of wave travel, the amplitude of reflected wave, the reflectance point, and the duration and pattern of ventricular ejection, especially with respect to change in heart rate and ventricular contractility. Aortic PWV, which is the speed of wave travel, represents intrinsically arterial stiffness, according to the Bramwell-Hill formula.4–6 Two articles7,8 in the present issue of Hypertension raise the issue of the predictive value of “surrogates of arterial stiffness” for CV events. Li et al7 studied the dynamic relationship between diastolic blood pressure (DBP0 and systolic blood pressure (SBP) in ambulatory blood pressure monitoring (ABPM) data throughout the day and calculated a novel index as 1− the regression slope of DBP on SBP. This index was named ambulatory arterial stiffness index (AASI) on the basis that “average distending BP …

Influence of pravastatin on carotid artery structure and function in dyslipidemic HIV-infected patients receiving antiretroviral therapy.

Abstract: Forty-two pravastatin-treated HIV-positive patients and 42 sex, age, and smoking status-matched hypercholesterolemic HIV-positive patients not under lipid-lowering treatment were compared for differences in intima-media thickness (IMT) of the common carotid artery (CCA) and aortic stiffness. Pravastatin had no influence on carotid artery structure and function, or aortic stiffness. Age and body mass index were independent determinants of IMT of the CCA. Mean arterial pressure, age, duration of HIV infection and protease inhibitor exposure determined aortic stiffness.

α1-antitrypsin gene polymorphisms are not associated with renal arterial fibromuscular dysplasia

Abstract: OBJECTIVE We previously showed that fibromuscular dysplasia (FMD) of the renal artery may be familial. Case reports have associated alpha1-antitrypsin deficiency and FMD. The aim of this study was to test the implication of the alpha1-antitrypsin (AAT) gene in a large cohort of patients with renal FMD. MATERIALS AND METHODS A case-control study comparing the genotype frequencies in 161 consecutive patients with angiographically proven renal FMD with those observed in three sets of controls (353 hypertensive patients, 288 normotensive patients, 444 normotensive women) was conducted. High-resolution echotracking of the carotid and radial arteries was performed in a subset of 77 FMD patients. Three functional polymorphisms of the AAT gene (PiM1, PiZ, PiS) were investigated. RESULTS Clinical (age 44.3 +/- 13.8 years, 85.1% women) and radiological (77.1% of multifocal lesions) characteristics of the FMD population were consistent with those previously published. No differences were found in AAT genotype frequencies in the FMD subjects compared with the 1085 controls. We found no correlation between the AAT genotypes and the clinical and angiographical characteristics of the FMD patients. Echotracking results confirmed our previously published results in FMD patients with a specific pattern and a mean arterial phenotypic score greater than 3. However, no difference in the arterial score was observed across the genotypes. CONCLUSION Polymorphisms PiM1, PiZ and PiS of the AAT gene are not associated with renal FMD or infraclinical carotid lesions detected by echotracking methods. As the true prevalence of renal FMD is not precisely known and alpha1-antitrypsin deficiency is not infrequent in the general population, the association of the two may occur by chance.

Pulse pressure reduction and cardiovascular protection.

Abstract: Brachial pulse pressure (PP) is now a well-established cardiovascular risk factor. Central rather than peripheral PP should be measured to determine the 'true' haemodynamic effects of antihypertensive agents on target organs. Peripheral PP, measured at the brachial artery, does not reflect central PP (either carotid or ascending aorta), because their determinants are different and pathophysiological conditions and drugs may change central PP without changing peripheral PP. Central PP (i.e. carotid artery or ascending aorta) has shown an independent predictive value for all-cause mortality in patients with end-stage renal disease and in the hypertensive patients of the CAFE study. Antihypertensive treatment has repeatedly demonstrated its ability to prevent cardiovascular events. Whether the effect on cardiovascular events in clinical trials comparing two pharmacological classes or two therapeutic strategies is, at least partly, the result of differential effects on PP remains to be demonstrated. It is therefore of major importance to determine which therapeutic strategies may differentially lower central PP, and in turn reduce cardiovascular events. In clinical practice, lowering PP is often a difficult task, particularly in diabetic hypertensive individuals. In the PARADIS study, we aimed to determine, in a population of hypertensive patients with both type 2 diabetes and PP greater than 60 mmHg, which clinical characteristics predict the fall in PP on treatment and a reduction in cardiovascular events. The reinforcement of therapeutic measures, including a fixed low-dose perindopril/ indapamlde combination, made possible the effective lowering of PP and cardiovascular events in type 2 diabetic hypertensive patients, under conditions of usual care by general practitioners and specialists.

Ambulatory arterial stiffness index derived from 24-hour ambulatory blood pressure monitoring. Commentary

Abstract: We hypothesized that 1 minus the slope of diastolic on systolic pressure during 24-hour ambulatory monitoring (ambulatory arterial stiffness index [AASI]) might reflect arterial stiffness. We compared AASI with established measures of arterial stiffness and studied its distribution in Chinese and European populations. We used 90207 SpaceLabs monitors and the SphygmoCor device to measure AASI, central and peripheral pulse pressures, the central (CAIx) and peripheral (PAIx) systolic augmentation indexes, and aortic pulse wave velocity. In 166 volunteers, the correlation coefficient between AASI and pulse wave velocity was 0.51 (P<0.0001). In 348 randomly recruited Chinese subjects, AASI correlated (P<0.0001) with CAIx (r=0.48), PAIx (r=0.50), and central pulse pressure (r=0.50). AASI increased with age and mean arterial pressure but decreased with body height. Both before and after adjustment for arterial wave reflections by considering height and heart rate as covariates, AASI correlated more (P<0.0001) closely with CAIx and PAIx than 24-hour pulse pressure. Among normotensive subjects, the 95th percentile of AASI was 0.55 in Chinese and 0.57 in 1617 Europeans enrolled in the International Database on Ambulatory Blood Pressure Monitoring. The upper boundary of the 95% prediction interval of AASI in relation to age ranged from 0.53 at 20 years to 0.72 at 80 years. In conclusion, AASI is a new index of arterial stiffness that can be easily measured under ambulatory conditions. Pending additional validation in outcome studies, normal values of AASI are probably <0.50 and 0.70 in young and older subjects, respectively.