Safar M

Reversion of cardiac hypertrophy and reduced arterial compliance after converting enzyme inhibition in essential hypertension.

Blood pressure, forearm arterial hemodynamics (with a pulsed Doppler flowmeter), and echocardiographic parameters were studied in 16 patients with sustained essential hypertension before and 3 months after administration of the converting enzyme inhibitor perindopril. In a single-blind study versus placebo, it was shown that perindopril significantly reduced blood pressure (p less than 0.01), whereas there was an increase in brachial blood flow (p less than 0.01) because of a simultaneous increase in blood flow velocity (p less than 0.01) and arterial diameter (p less than 0.01). During a 5-minute period of wrist occlusion, blood flow velocity was reduced to a greater extent with perindopril than with placebo (p less than 0.001), whereas corresponding reductions in arterial diameter were equivalent, indicating that the increase in diameter after perindopril could not be explained simply on the basis of flow-dependent dilatation. During active treatment, brachial artery compliance increased (p less than 0.01) and pulse wave velocity decreased (p less than 0.01), whereas there was no change in the tangential tension of the arterial wall, defined as the product of mean arterial pressure and arterial diameter. Four weeks after treatment was stopped, blood pressure and forearm arterial hemodynamics returned toward baseline values. Cardiac mass was significantly decreased after perindopril (p less than 0.01) and remained decreased 4 weeks after cessation of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of atorvastatin on aortic pulse wave velocity in patients with hypertension and hypercholesterolaemia : a preliminary study

As statins may contribute to plaque stabilisation, it is important to evaluate whether these drugs may modify arterial stiffness. In 23 patients, aged 32–70 years, with hypertension and hypercholesterolaemia, a double-blind randomised study vs placebo was performed to evaluate whether atorvastatin was able to modify aortic stiffness, measured from aortic pulse wave velocity (PWV), after a 12-week treatment. The results revealed that atorvastatin did not change blood pressure, significantly lowered (P<0.003; <0.002) plasma total and LDL cholesterol, and increased aortic PWV by +8% (vs −2% under placebo) (P⩽0.05). The percentage changes in plasma total and LDL cholesterol and in PWV were significantly and negatively correlated, independent of blood pressure level. The finding of increased aortic PWV after 12-week statin treatment agrees with studies in monkeys, indicating that, at the early phase of hypolipidaemic diet but not later, aortic PWV increases transiently as a consequence of the significant reduction of lipid vascular content. In conclusion, the present results support the possibility that statins might contribute to a change in arterial stiffness independent of blood pressure level, and suggest that long-term studies in humans are needed to evaluate the contribution of arterial elasticity to statin-induced vascular remodelling.

Peripheral Pulse Pressure, Large Arteries, and Microvessels

The aorta is a capacitance vessel that enables transformation of the “on-off” blood-flow characteristics of the left ventricle into a less pulsatile flow in more distal vessels. Thus, a smooth nonpulsatile blood-flow pattern is achieved at capillary level. Arterial wall stiffness determines the degree of energy absorbed by the elastic aorta and its recoil in diastole. Aortic pulse pressure (PP) in health is physiologically lower than peripheral PP. Reduction of elevated aortic systolic blood pressure (SBP) protects circulation from pressure-induced damage. Maintaining aortic diastolic blood pressure (DBP) ensures adequate coronary perfusion. A stiffer aorta, which can be observed with aging and in different pathological conditions such as hypertension, obesity, diabetes mellitus, and dyslipidemia, fails in both of these tasks. Numerous studies now show that PP, arterial stiffness, and early wave reflections are strong predictors of cardiovascular (CV) risk.1 The CV complications are usually located above the aortic recoil and mainly affect the heart. The downward consequences of enhanced pulsatility, particularly at the peripheral and even the microvascular levels, are less documented. The study by Mitchell et al2 in the June issue of Hypertension addresses this subject, with particular focus on a healthy elderly population. In addition to arterial stiffness, the pulse waveform characteristics are influenced by wave reflection. Energy propagated through the circulation usually meets vessel branching points, at which some of the antegrade energy is “reflected” and becomes retrograde. At some point through the aorta and its braches, the incident and reflected waves summate. Where and when this happens …

Structural and functional arterial properties in patients with obstructive sleep apnoea syndrome and cardiovascular comorbidities.

The increased severity of obstructive sleep apnoea syndrome (OSAS) is associated with a parallel increase in the incidence of cardiovascular events. Whether the increased severity of OSAS is in fact associated with impaired arterial properties has never been thoroughly studied. In patients with OSAS who carry a high burden of cardiovascular risk factors, we investigated whether the severity of OSAS is associated with deterioration in the arterial properties, independent of classical cardiovascular risk factors. In 74 consecutive patients with OSAS, we non-invasively assessed, by means of tonometry and high-resolution ultrasound: carotid intima-media thickness (IMT), carotid diameter and plaques, carotid-femoral pulse wave velocity (PWV), central augmentation index (AI) and central blood pressures. The respiratory disturbance index was an independent predictor of IMT and PWV but not of carotid plaques, carotid diameter, AI or central blood pressures. Several parameters of nocturnal hypoxaemia were independently correlated with carotid IMT and PWV. In conclusion, arterial stiffening and thickening are modulated by the severity of OSAS, independently from age and cardiovascular risk factors.

Arterial Stiffness: A Simplified Overview in Vascular Medicine

Arterial elasticity is a common index of medical semiology, easier to understand than blood pressure measurement. This chapter summarizes the most classical aspects which are important to understand in vascular medicine.

Differences between cardiac and arterial fibrosis and stiffness in aldosterone-salt rats: effect of eplerenone.

Background. Previous experiments have studied separately the development of either cardiac or aortic fibrosis and stiffness in aldosterone (Aldo)-salt hypertensive rats. Our aim was to determine in vivo the effects of Aldo and the Aldo receptor antagonist eplerenone (Epl) on simultaneous changes in cardiac and arterial structure and function and their interactions. Methods and Results. Aldo was administered in uninephrectomised Sprague-Dawley rats receiving a high-salt diet from 8 to 12 weeks of age. Three groups of Aldo-salt rats were treated with 1 to 100 mg/kg-1. d-1 Epl by gavage. Arterial elasticity was measured by elastic modulus (Einc)-wall stress curves using medial cross-sectional area (MCSA). The cardiac and arterial walls were analysed by histomorphometry (elastin and collagen), immunohistochemistry (EIIIA fibronectin, Fn), and Northern blot (collagens I and III). Aldo caused increased systolic blood pressure (SBP), carotid Einc, MCSA, and EIIIA Fn with no change in wall stress or elastin and collagen densities. No difference in collagen mRNA levels was detected between groups. During the same period, cardiac mass and collagen mRNA and protein levels increased markedly in the myocardial tissue. Epl normalised collagen in the myocardium, Eincwall stress curves, MCSA, and EIIIA Fn in Aldo rats. These dose-dependent effects were not accompanied by a consistent reduction in SBP and cardiac mass. Conclusions. In exogenous hyperaldosteronism in the rat, Aldo causes independently myocardial collagen and arterial Fn accumulation, the latter being responsible for increased intrinsic carotid stiffness. Epl prevents both cardiac and arterial effects but does not reduce consistently SBP.

Association between pulse pressure, carotid intima–media thickness and carotid and/or iliofemoral plaque in hypertensive patients

Increased common carotid artery intima–media thickness (CCA-IMT) and carotid and/or iliofemoral (C/IF) plaque are frequent in subjects treated for hypertension, but their association with pulse pressure (PP) has rarely been studied. Using ultrasound techniques, CCA-IMT and C/IF plaques were studied in 323 hypertensive subjects, who were classified into four groups according to the adequacy of blood pressure (BP) control (systolic BP (SBP) <140 mmHg and diastolic BP (DBP) <90 mmHg) and PP (high or low). After adjustment for confounding variables, an increase in CCA-IMT was the only factor significantly and independently associated with high PP, irrespective of the effectiveness of blood pressure control and of antihypertensive drug treatment. CCA-IMT correlated with age, PP, waist-to-hip ratio, tobacco consumption, and heart rate. C/IF plaques correlated with age, tobacco consumption, diabetes mellitus, and dyslipidaemia. To conclude, even with SBP<140 mmHg and DBP<90 mmHg on treatment, hypertensive subjects may have increased CCA-IMT values and C/IF plaque. Four cardiovascular risk factors seem to be involved in these alterations, namely tobacco consumption, dyslipidaemia, diabetes and increased PP. Only the latter factor does not have a standardized effective treatment.

Association of current weight and birth weight with blood pressure levels in saharan and European teenager populations

BACKGROUND The Saharan adult population is characterized by a high prevalence of hypertension. The aim of the present study was to compare blood pressure (BP) levels in Saharan Arab-origin teenagers, in relationship with Europeans of the same age, and to assess the association with birth weight, body weight, and other anthropometric measurements. METHODS BP values, heart rate (HR), clinical parameters, and anthropometric measurements were determined in 2,057 teenagers ages 15-19, 1,122 Algerians (388 boys) and 935 Italians (407 boys). Birth weight was obtained from obstetrical records in 568 Algerians and 735 Italians. RESULTS The European teenagers were significantly taller and heavier than their Algerian counterparts. In the Algerian population, systolic BP (SBP) was higher in boys (P < 0.01) and lower in girls (P < 0.0001) compared to the Italians, whereas diastolic BP (DBP) was higher in Italians (P < 0.001). Both SBP and DBP were higher in boys than in girls independently of geographic origin (P < 0.001). In all four gender and ethnic groups, both SBP and DBP were strongly correlated with weight or body mass index (BMI). Influence of body weight was stronger on SBP than on DBP; in all four groups, those with the highest weight or BMI quartiles had higher SBP levels by 6-12 mm Hg as compared to those individuals in the lowest quartiles. No correlation was found between birth weight, and SBP or DBP. CONCLUSIONS In Algerian and Italian teenagers, both male and female, current weight but not birth weight was found to be a strong determinant of BP levels.

Aortic stiffness, inflammation, denutrition and prognosis in the oldest people.

Observational studies have shown that some of the classic CV risk factors, namely hypertension or hypercholesterolemia, become nebulous, or even act in the reverse direction, in the oldest people. We investigated whether in the elderly, increased aortic stiffness was associated with higher mortality risk, before and after adjustments on common geriatric confounders. In a cohort of 331 (86 men) subjects aged >70 years (mean age (±s.d.): 85±7 years), aortic stiffness was assessed by carotid–femoral pulse wave velocity (PWV). Classical CV risk factors were determined simultaneously, in association with inflammation and denutrition parameters. One hundred and ten subjects died during a 2-year follow-up period. In crude analysis, a positive non-significant trend was observed between PWV and mortality risk. Multivariate Cox regression analysis showed that five parameters entered the prediction model: two were positively related to mortality risk, PWV (P=0.008) and orosomucoide (P=0.045), and three were related negatively, total cholesterol (P=0.006), albumin (P=0.026) and body weight (P=0.035). Interaction analysis revealed that the effect of PWV on mortality was increased in the presence of renal dysfunction and increased inflammation. In conclusion, although marginally significant in crude analysis, PWV is a powerful determinant of prognosis in the oldest people taking into account inflammation and denutrition.

Pulse Pressure and Antihypertensive Agents

In their subanalysis of the LIFE study,1 the authors conclude that they “show superior protection against stroke in patients treated with losartan when compared with atenolol … This difference may be related to specific effects of angiotensin type 1 receptor antagonism … beyond blood BP reduction.” The authors do not consider the alternative hypothesis: that the changes in pulse pressure (PP) might differ markedly under losartan and atenolol and also according to the site of PP arterial measurements.2 As a consequence of differences in arterial stiffness and timing of wave reflections along the arterial tree, PP is lower in central than in peripheral arteries, whereas mean arterial pressure (MAP) is nearly the same. This phenomenon is attenuated in aged people and in the presence of bradycardia.2 Thus, mechanical forces at the site of target organ damage are not accurately measured by the brachial BP cuff. Furthermore, antihypertensive agents may cause the same MAP reduction at the brachial …