[Value of arterial rigidity measurements in cardiovascular pathology].
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Aorta↗
Biomedical subjects
X Girerd
Publications and source records attributed to X Girerd.
[Blood pressure parameters and cardiovascular risk in the elderly].
The treatment decision must take into account the benefit and risks related to the intervention: the benefit demonstrated and quantified in many therapeutic trials in hypertension in the elderly, but also the patient's initial risk. It is now recognized that, in elderly hypertensive patients, systolic blood pressure is a better predictor of morbid and lethal events related to hypertension than diastolic blood pressure. Recent data in the medical literature attribute a predictive role to pulse pressure which is even greater than that of systolic blood pressure. From a pathophysiological point of view, the level of pulse pressure reflects the degree of rigidity of large arterial trunks. The arterial rigidity parameter could integrate the harmful effect of "cardiovascular risk factors" (hypertension, but also atherogenic dyslipidaemia, diabetes, smoking, homocysteine, genetic factors, etc.) on the years or decades of exposure, and pulsed pressure would therefore appear to be a better marker of cardiovascular risk than other blood pressure parameters. Pulse pressure should therefore be integrated into the benefit/risk ratio of antihypertensive treatment in the elderly.
Age Distribution↗
[Benefits of hypertension treatment in the elderly].
The benefits of treatment of hypertension in the elderly have been demonstrated by the results of therapeutic trials conducted in subjects over the age of 60. In 1985, the EWPHE trial, which demonstrated that thiazide diuretics decreased the main cardiovascular complications observed in elderly hypertensives, opened the way to the demonstration of the preventive efficacy of other classes of antihypertensives. The high level of cardiovascular risk observed in the elderly explains why prescription of antihypertensives provides a greater benefit in elderly hypertensives than in younger hypertensives. In hypertensive patients over the age of 80, the benefits of drug-induced blood pressure reduction have been demonstrated in terms of prevention of nonfatal complications.
Adrenergic beta-Antagonists↗
Prevention of dementia in randomised double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial.
BACKGROUND: Systolic hypertension increases the risk of dementia in elderly people. The vascular dementia project, set up in the framework of the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial, investigated whether antihypertensive drug treatment could reduce the incidence of dementia. METHODS: Eligible patients had no dementia, were at least 60 years old, and had a blood pressure when seated of 160-219 mm Hg systolic and below 95 mm Hg diastolic. Active treatment consisted of nitrendipine (10-40 mg/day) with the possible addition of enalapril (5-20 mg/day), hydrochlorothiazide (12.5-25 mg/day), or both drugs, titrated or combined to reduce the systolic blood pressure by at least 20 mm Hg to reach a value below 150 mm Hg. Cognitive function was assessed by the mini mental state examination (MMSE). If the MMSE score was 23 or less, diagnostic tests for dementia were done (DSM-III-R criteria). The cause of dementia was established by the modified ischaemic score with brain imaging or the Hachinski score. FINDINGS: Median follow-up by intention to treat was 2.0 years. Compared with placebo (n=1180), active treatment (n=1238) reduced the incidence of dementia by 50% from 7.7 to 3.8 cases per 1000 patient-years (21 vs 11 patients, p=0.05). The median MMSE score at randomisation was 29 in both treatment groups. At the last available assessment, systolic and diastolic blood pressure were, respectively, 8.3 mm Hg and 3.8 mm Hg lower (p<0.001) in the active-treatment group, but on average the MMSE scores did not change in either group. In the control patients, however, the MMSE decreased (p=0.04) with decreasing diastolic blood pressure, whereas in the active-treatment group MMSE scores improved slightly (p=0.01) with greater reduction in diastolic blood pressure (p=0.002 for between-group difference). INTERPRETATION: In elderly people with isolated systolic hypertension, antihypertensive treatment was associated with a lower incidence of dementia. If 1000 hypertensive patients were treated with antihypertensive drugs for 5 years 19 cases of dementia might be prevented.
Aged↗
Effects of norepinephrine on the mechanical properties of the human radial artery in vitro.
BACKGROUND: The human radial artery has been proposed as an alternative to coronary grafts in subjects with coronary ischemic disease. Because this muscular artery is known to be prone to spasm, changes in its mechanical properties in response to catecholamines are important to investigate. METHODS: We describe a new echo-tracking technique of high resolution that allows investigation, in vitro, of the diameter and the wall thickness of arterial cylindrical segments. In addition, a classic tissue bath experiment is used to study the vasoreactivity of arterial rings. Mechanical properties of the radial artery are determined over a 0 to 200 mm Hg range of transmural pressure in the presence and absence of norepinephrine in the perfusion medium. RESULTS: With tissue bath experiments, the norepinephrine dose-response curve was characterized by an EC50 value of 1.48+/-1.09 10(-6) mol/L and a maximal developed tension at 10(-5) mol/L. The results obtained with pressurized segments gave similar results with an EC50 value of 8.1+/-2.3 10(-7) mol/L and a maximal change in diameter at 10(-5) mol/L norepinephrine. Under the influence of 10(-5) mol/L norepinephrine, the radial artery constriction reached 22%, significantly affecting the unstressed diameter. Compliance did not show any significant change in the overall transmural pressure range, whereas distensibility significantly increased and elastic modulus significantly decreased. CONCLUSION: The study shows that the capacitive properties of the human muscular radial artery are maintained with norepinephrine not only through decreased stiffness of wall material but also through reduced unstressed diameter. Thus drugs inducing smooth muscle relaxation may be helpful in preventing radial artery spasm after coronary grafts.
Aged↗
Comparative reactivity and mechanical properties of human isolated internal mammary and radial arteries.
OBJECTIVE: The aim of this study was to analyse the arterial wall mechanics and the vasoreactive properties of the radial artery in comparison with those of the internal mammary artery and to discuss their implications for coronary bypass grafts. METHODS: Measurements of pressure and diameter were obtained from cylindrical segments, whereas measurements of reactivity were obtained from ring segments from the same arteries. We used an echo-tracking technique of high resolution enabling to investigate, in vitro, the diameter and the wall thickness of arterial cylindrical segments. Furthermore, the compliance, distensibility and incremental elastic modulus of the radial and of the mammary arteries were determined for a wide range of transmural pressure (0-200 mmHg) in presence and absence of norepinephrine (NE). RESULTS: Our results show that NE caused vasoconstriction of the two arteries. Strain was found significantly higher for the radial artery than for the internal mammary artery at any given value of stress both in the presence and in the absence of NE. In presence of NE, compliance for radial artery, in the overall transmural pressure range, did not change, whereas, distensibility was significantly increased and the elastic modulus was significantly decreased. Under the same conditions, the distensibility of the mammary artery tended to decrease and its elastic modulus to increase. In parallel, the vasoreactive properties of the two arteries confirmed the previous results showing that radial artery developed a significant higher tension to vasoconstricting agents (KCl, NE and phenylephrine (PHE)) and higher relaxation to isradipine than internal mammary artery. Moreover, radial artery displayed a lesser sensitivity to sodium nitroprusside than internal mammary artery. Furthermore, sensitivity to NE was found to be 7-fold higher for radial artery than for internal mammary artery. CONCLUSION: Taken together, data on the mechanical and reactive properties of radial and internal mammary arteries show why the radial artery displayed a higher potential for spasm than the internal mammary artery and why the use of Ca2+ channel blocker can decrease the incidence of occlusion and spasm.
Biomechanical Phenomena↗
Differential responses of the heart and vasculature to chronic blood pressure reduction in essential hypertension.
BACKGROUND: In subjects with hypertension, converting enzyme inhibitors and calcium entry blockers may decrease arterial stiffness independently of blood pressure changes, but the heterogeneity of response of the arterial tree has never been taken into account. MATERIAL AND METHODS: In 31 subjects with hypertension, we determined through the use of Doppler echographic techniques the compliance and distensibility of the common carotid and femoral arteries and of the abdominal aorta, the radial artery wall thickness, and cardiac mass. In a double-blind randomized study, the converting enzyme inhibitor ramipril and the calcium entry blocker nitrendipine were studied and compared during 12 weeks treatment, then 4 weeks after treatment was stopped. RESULTS: The two drugs caused significantly different plasma levels of active renin, angiotensin I, and norepinephrine but the same effects on blood pressure, cardiac mass, radial artery wall thickness, and stiffness indices. In contrast, the effect of treatment differed substantially according to the site of cardiovascular measurements. Although cardiac mass decreased significantly in parallel with blood pressure reduction, no change in radial artery wall thickness occurred. Carotid compliance and distensibility increased significantly, even after drug treatment was stopped, whereas little or no change was observed for the femoral artery and the abdominal aorta. CONCLUSION: This study provides evidence that the changes in cardiovascular structure and function with ramipril and nitrendipine treatment are poorly influenced by their different mechanisms of action but highly dependent on the site of measurements. The results suggest that local autocrine-paracrine mechanisms act synergistically with blood pressure to produce cardiovascular changes.
Adult↗
[Conn adenoma manifesting as reversible tetraparesis and rhabdomyolysis].
INTRODUCTION: Primary hyperaldosteronism is an uncommon cause of hypertension which classically features hypokaliemia, metabolic alkalosis and excessive urinary potassium excretion. Clinical manifestations of hypokalemia rarely reveal the diagnosis. EXEGESE: We report the case of a hypertensive patient who developed quadriparesis and rhabdomyolysis induced by a severe hypokalemia. Clinical manifestations were reversible after potassium supplementation. Laboratory and radiological findings led to the diagnosis of an aldosterone-producing adenoma. Surgical treatment allowed correction of electrolyte abnormalities and improvement of hypertension. CONCLUSION: Although primary aldosteronism is rare, it should be systematically considered when arterial hypertension is associated with hypokalemia, even if the potassium depletion is due to diuretic therapy.
Adenoma↗
Regression of radial artery wall hypertrophy and improvement of carotid artery compliance after long-term antihypertensive treatment in elderly patients.
OBJECTIVES: The present study was designed to assess whether a diuretic- or an angiotensin-converting enzyme inhibitor-based treatment can reduce arterial wall hypertrophy of a distal muscular medium-sized artery--the radial artery--and the stiffness of a proximal large elastic artery--the common carotid artery. BACKGROUND: Large-artery wall thickness and stiffness are increased during sustained essential hypertension and contribute to the increased risk of complications. Whether antihypertensive treatment can normalize the wall hypertrophy of conducting arteries has not yet been determined. METHODS: Seventy-seven elderly hypertensive patients were randomized to receive 9 months of double-blind treatment with perindopril (2 to 8 mg/day) or the diuretic combination of hydrochlorothiazide (12.5 to 50 mg/day) plus amiloride (1.25 to 5 mg/day) after a 1-month placebo washout period. If systolic blood pressure remained at >160 mm Hg after 5 months, chlorthalidone or atenolol was added, respectively. Arterial variables, including radial artery mass and common carotid artery compliance, were calculated from noninvasive measurements of internal diameter and wall thickness with the use of high resolution echo-tracking systems at baseline and after 5 and 9 months. RESULTS: During treatment, blood pressure and arterial variables changed to the same extent in both groups. After a 9-month treatment, systolic, diastolic and pulse pressures and radial artery wall thickness, mass and thickness/radius ratio decreased significantly (p < 0.01), whereas carotid compliance increased (p < 0.001). The decrease in radial artery thickness/radius ratio after a 9-month treatment was significantly related to the reduction in pulse pressure (p < 0.01), whereas the improvement in carotid compliance was related to the reduction in mean arterial pressure (p < 0.01). In healthy subjects and untreated hypertensive patients, radial artery diameter, wall thickness and thickness/radius ratio and carotid artery compliance did not change significantly during a 9-month observation period. CONCLUSIONS: These results indicate that in elderly hypertensive patients, both angiotensin-converting enzyme inhibitor- and diuretic combination-based treatments can reduce radial artery wall hypertrophy and improve carotid artery compliance.
Aged↗
Correlates of cognitive status of old patients with isolated systolic hypertension: the Syst-Eur Vascular Dementia Project.
OBJECTIVE: To assess cognitive functions and their correlates for a dementia-free cohort of old patients with isolated systolic hypertension. DESIGN: Cross-sectional data from the randomization period of the European Trial in Elderly with Systolic Hypertension (Syst-Eur Vascular Dementia Project). SETTING: Sixteen European countries and Israel. PARTICIPANTS: We studied 2252 patients aged 60-100 years (mean 70). MAIN OUTCOME MEASURES: Mini Mental State Examination (MMSE) and Spearman correlation of MMSE scores to demographic data or blood pressure. RESULTS: The MMSE was successfully completed for 1474 women and 751 men. The baseline blood pressure averaged 173 +/- 10/86 +/- 6 mmHg (means +/- SD). Median age at which education of patients at school had stopped was 15 years. Men and women who consumed alcohol (28%) had median intakes of 8 and 3 g/day, respectively. The median MMSE score was 29 (range 15-30). The maximum score of 30 was attained by 609 (30%) subjects. Fifty-nine (3%) patients had a MMSE score of 23 or less. The MMSE score decreased with advancing age (r = -0.21, P < 0.001). Both for men and for women, it was positively correlated to the level of education (r = 0.30 and r = 0.32, P < 0.001). For women after adjustment for age and the level of education, the score was correlated negatively to systolic blood pressure (r = -0.07, P < 0.05) but positively to intake of alcohol (r = 0.06, P < 0.05). CONCLUSION: In a cohort of elderly patients with isolated systolic hypertension, baseline cognitive function measured in terms of the MMSE score was high, probably due to selective recruitment of patients who were not clinically demented. Blood pressure was a weak contributor to cognitive status compared with age and level of education. Baseline cognitive function of women was negatively and independently correlated to systolic blood pressure.
Aged↗
Opposite effects of plasma homocysteine and the methylenetetrahydrofolate reductase C677T mutation on carotid artery geometry in asymptomatic adults.
Studies of symptomatic patients have identified hyperhomocysteinemia as an independent risk factor for vascular disease. In case-control studies, a point mutation (C677T) in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) has also been linked to an increased risk of vascular disease through its effect on homocysteinemia. Our aim was to extend these observations to asymptomatic subjects by studying the influence of both homocysteinemia and its mutation on carotid artery geometry. We examined 144 subjects free of atherosclerotic lesions. Fasting homocysteinemia was measured by high-performance liquid chromatography with fluorometric detection. MTHFR genotype was analyzed by polymerase chain reaction followed by HinfI digestion. Carotid artery geometry was characterized by internal diameter and intima-media thickness, as assessed by a high-resolution echo-tracking system. Subjects in the upper homocysteine tertile had a greater carotid internal diameter than did subjects in the middle and lower tertiles (6516+/-770 versus 6206+/-641 and 5985+/-558 microm, respectively; P<0.001). Subjects homozygous for the mutation had a smaller carotid artery internal diameter than did subjects heterozygous or homozygous for the wild-type allele (5846+/-785 versus 6345+/-673 and 6199+/-671 microm, respectively; P<0.05). Homocysteinemia was not significantly increased in subjects homozygous for the mutation. In multivariate regression analysis, homocysteinemia was independently and positively associated with lumen diameter (P=0.0008) and wall thickness (P=0.020). Conversely, homozygosity for the mutation was negatively associated with internal diameter (P=0.009). These preliminary data suggest that mildly elevated homocysteinemia and homozygosity for the MTHFR C677T mutation are associated with opposite preclinical modifications of carotid artery geometry. If confirmed, these results may have important implications for new treatment strategies for vascular disease before the onset of clinical manifestations.
Adult↗
Opposite effects of remodeling and hypertrophy on arterial compliance in hypertension.
Sustained hypertension is associated with a reduction in large artery compliance. However, we previously showed that, at the site of the radial artery, a distal muscular artery, the compliance of hypertensive patients was not significantly different from those of normotensive controls when the two groups were studied at their respective mean arterial pressures, despite increased wall thickness in hypertensives. To determine whether this paradoxical finding could be related to a specific pattern of geometrical changes, we studied arterial compliance in never-treated hypertensive patients characterized either by radial artery hypertrophy or remodeling, and compared them to normotensive controls. By analogy with Devereux's classification for left ventricular hypertrophy, we defined remodeling as an increased thickness to radius ratio (h/r) and a normal vascular mass (VM), and arterial hypertrophy as an increased VM irrespective of the values of h/r. Internal diameter and wall thickness were measured at the site of the radial artery using a high resolution echo-tracking system. The lumen cross-section-pressure curve was determined from the two simultaneous and continuous recordings of arterial diameter and blood pressure. Then, the cross-sectional compliance (CC)-pressure curve was calculated. Isobaric compliance was calculated at 100 mm Hg. Thresholds for h/r and VM were determined according to gender as the 95th percentile of a group of 100 normotensive subjects. The group of hypertensive patients included 58 patients with hypertrophy (h/r: 0.25+/-0.04; VM: 31+/-6 mg/cm; mean+/-SD) and 25 patients with remodeling (h/r: 0.29+/-0.06; VM: 20+/-4 mg/cm) and was compared to a group of 50 age- and gender-matched normotensives (h/r: 0.16+/-0.02; VM: 17+/-4 mg/cm). Compared to normotensives, isobaric compliance of the radial artery was increased in hypertensive patients with hypertrophy (HH) whereas it was not different in hypertensive patients with remodeling (RH). These results indicate that compliance is dependent on hypertrophy or remodeling pattern and suggest that in the face of hypertension, only arterial hypertrophy is an adaptive process leading to normal operating compliance through an increased isobaric compliance.
Blood Pressure↗
Lack of association between renin-angiotensin system, gene polymorphisms, and wall thickness of the radial and carotid arteries.
To investigate the relationship between polymorphisms of the angiotensin-converting enzyme (ACE) and the angiotensin II type 1 receptor (AT1R) genes and structural phenotypes of arteries, we studied a cohort of 340 subjects (aged 49+/-12 years) without evidence of cardiovascular disease and who had never been treated previously with any cardiovascular treatments. Structural phenotypes (wall thickness and internal diameter) were evaluated for the common carotid and the radial arteries using high-resolution echo-tracking devices (NIUS-02 and Wall Track System). The influence of ACE insertion/deletion (I/D) and AT1R A/C1166 polymorphism genotypes on structural parameters was tested by ANOVA and logistic regression analysis. For the radial artery, mean wall thickness among subjects according to the ACE I/D or AT1R A/C1166 genotypes was not different. This lack of association persisted in a logistic regression analysis or when the comparison was restricted to a subgroup of subjects potentially at high genetic risk (DD and CC or AC) compared with subjects at low genetic risk (AA and II or ID). Also, no association was observed between the carotid artery intima-media thickness and the 2 polymorphisms. In conclusion, the ACE I/D and the AT1R A/C1166 gene polymorphisms are not markers of vascular hypertrophy in subjects with no evidence of cardiovascular disease. These results suggest that these gene polymorphisms have an undetectable role in the geometry of the radial and carotid arteries compared with usual determinants such as blood pressure and age.
Adult↗
Improved tolerability of felodipine compared with amlodipine in elderly hypertensives: a randomised, double-blind study in 535 patients, focusing on vasodilatory adverse events. The International Study Group.
The primary aim of this double-blind, parallel group trial was to compare incidence of newly occurring vasodilatory adverse events in elderly patients treated with recommended once-daily doses of felodipine extended release (ER) or amlodipine. A total of 535 patients over 65 years old with a sitting diastolic blood pressure of 90-115 mmHg and/or systolic blood pressure 160-220 mmHg, were recruited at 46 centres worldwide. Patients were randomised to felodipine ER 2.5 mg or amlodipine 5 mg. If blood pressure was > 160/90 mmHg after three or six weeks, felodipine ER was increased to 5 and 10 mg and amlodipine to 10 mg. After nine weeks, average doses of felodipine ER and amlodipine were 5.5 mg and 7.3 mg, respectively. Newly occurring vasodilatory adverse events were reported by 32% of felodipine ER patients and 43% of amlodipine patients (p = 0.007). Both treatments effectively reduced blood pressure 24 hours post-dose. Using a low starting dose and individual titration, felodipine ER achieves good control of blood pressure with few vasodilatory side-effects.
Aged↗
[Conn's syndrome. Study of systemic cardiovascular hemodynamics after medical treatment with spironolactone and after surgical treatment].
OBJECTIVES: Assess hemodynamic effect of Conn's syndrome in order to better prepare patients for surgical resection of their adenoma. PATIENTS AND METHODS: Hemodynamic investigations were conducted before any treatment in 13 patients with Conn's syndrome. Results were compared with those in 13 control subjects with permanent primary hypertension. In the 13 patients with Conn's syndrome, the same hemodynamic parameters were studied in 13 after drug therapy using spironolactone and in 8 after surgery. RESULTS: Hypertension was associated with a significant increase in stroke volume and a non-significant increase in cardiac index. Blood pressure normalized after sprironolactone and after surgery in parallel with a significant decrease in blood volume. DISCUSSION: These hemodynamic disorders in Conn's disease patients suggest that the increase in stroke volume is a consequence of increased venous return and more likely, in myocardium contractility or a combination of both. CONCLUSION: These hemodynamic characteristics of Conn's disease should be useful in guiding monitoring schemes for these patients in the perioperative period.
Adolescent↗
[Acute hypertensive crisis. Diagnosis and management in emergency situation].
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Acute Disease↗
Carotid-artery dissection after a prolonged telephone call.
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Adult↗
Association between increased plasma levels of aldosterone and decreased systemic arterial compliance in subjects with essential hypertension.
We previously observed that, in subjects with essential hypertension, acute ouabain constricts the brachial artery diameter in the presence of spironolactone treatment, a finding that is not observed in the absence of aldosterone antagonist and therefore suggests a specific effect of aldosterone on the arterial wall. To evaluate whether aldosterone excess may contribute to modulate arterial function, we investigated 56 patients with sustained essential hypertension in comparison with 36 normotensive controls. Systemic arterial compliance was measured from intraarterial blood pressure and cardiac output measurements using a classical Windkessel model to determine the elasticity of the proximal arterial tree. Radial artery compliance was determined using a previously described echo tracking technique. In hypertensive, but not in normotensive, subjects, systemic arterial compliance was strongly and negatively correlated with plasma aldosterone. The correlation was observed even after adjustment for age and blood pressure. Plasma potassium and renin activity did not interfere in the correlation. Acute administration of diltiazem did not change systemic compliance but significantly decreased plasma aldosterone, suggesting that, in the presence of calcium blockade, the same compliance was achieved for a lower plasma aldosterone level. Taken together, these findings strongly suggest that significant interactions exist between aldosterone and central conduit arteries and that aldosterone might modulate arterial function in subjects with essential hypertension.
Adult↗