Showing papers by "Robert Fagard published in 1992"

Ambulatory blood pressure monitoring in elderly patients with isolated systolic hypertension.

Abstract: Objectives: This study compared clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension (Isti). Patients: Eighty-seven patients aged 260 years with ISH on clinic measurement were followed in the placebo run-in phase of the Syst-Eur trial. Methods: Clinic blood pressure was defined as the mean of two blood pressure readings on each of three clinic visits (six readings in total). Ambulatory blood pressure was measured over 24 h using non-invasive ambulatory blood pressure monitors. Results: Daytime ambulatory systolic pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereas diastolic pressure was, on average, similar with both techniques of measurement. In the 42 patients who had repeat measurements, clinic blood pressure levels and the amplitude of the diurnal blood pressure profile (fitted by Fourier analysis) were equally reproducible. However, both were less reproducible than ambulatory blood pressure levels. The repeatability coefficients, expressed as per cent of near gaximum variation (four times the standard deviation of a given measurement), were 52% and 45% for the clinic systolic and diastolic pressures, 56010 and 42% for the amplitude of the diurnal profile, and 29% and 26% for mean 24-h pressures. Conclusions: In older patients with ISH, clinic and ambulatory systolic blood pressure measurements may differ largely: the prognostic significance of this difference remains to be elucidated. Furthermore, in these patients the level of pressure is more reproducible by daytime ambulatory blood pressure measurement than by clinic measurement.

The increase in Blood Pressure with Age and Body Mass Index is Overestimated by Conventional Sphygmomanometry

Abstract: This cross-sectional study investigated whether the technique of blood pressure measurement used (conventional sphygmomanometry vs. ambulatory monitoring) affects the relation between blood pressure and both age and body mass index. Two independent data sets were analyzed. The first comprised 328 subjects (48% men) drawn from the population of a small Belgian town, and the second comprised 776 Irish bank employees (51% men). Age ranged from 17 years to 81 years, and body mass index (weight (kg)/height (m)2) ranged from 16.6 to 40.2. Twenty-four-hour ambulatory blood pressure was lower than blood pressure measured by a nurse in both the Belgian population sample (118/71 mmHg vs. 122/73 mmHg) and the Irish employees (118/72 mmHg vs. 119/76 mmHg). When blood pressure was measured by an observer, the well-established relations between systolic and diastolic blood pressure and both age and body mass index were evident. When the analyses were repeated using 24-hour measurements, the increment (cross-sectionally assessed) in blood pressure with age was weaker, especially in young and middle-aged subjects (20-60 years), while the increase in blood pressure with body mass index was also reduced. The within-subject differences between the conventional and ambulatory blood pressure measurements increased with older age and greater body mass index. Several other relations with blood pressure as the response variable may require revision in light of the present findings.

Erythrocyte membrane lipids and cationic transport systems in men.

Abstract: OBJECTIVE The relationship between erythrocyte membrane and plasma lipids and various transmembrane erythrocyte cationic fluxes was examined in 53 normal men. DESIGN Different measurements of erythrocyte transport systems were obtained: Na(+)-Li+ countertransport activity; Na+, K+ cotransport activity; Na+, K(+)-ATPase pump activity and the ground membrane permeability for Na+ and K+ as well as the intra-erythrocyte Na+, K+ and Mg2+ concentrations. Plasma cholesterol, triglycerides, phospholipids, free fatty acids, low- and high-density lipoprotein cholesterol levels and the erythrocyte membrane contents of cholesterol, phospholipids and free fatty acids were obtained from fasting subjects. RESULTS In single regression analysis the erythrocyte Na(+)-Li+ countertransport and Na+, K+ cotransport activities were negatively related to the erythrocyte membrane cholesterol, phospholipids and free fatty acids contents. The Na+, K(+)-ATPase pump activity as assessed by the ouabain-sensitive Na+ efflux was also inversely related to the membrane cholesterol and phospholipids contents. In multiple regression analysis the red blood cell Na(+)-Li+ countertransport activity was independently and negatively related to the membrane cholesterol and free fatty acids contents. CONCLUSION Our data show that an elevated level of erythrocyte membrane lipids in normal men is accompanied by lower Na(+)-Li+ countertransport, Na+, K+ cotransport and Na+, K(+)-ATPase pump activities.

Automated versus observer blood pressure as determinants of left ventricular structure.

Abstract: We studied the contribution of automated blood pressure measurements to the variation in left ventricular structural characteristics, independent of pressure measured by an observer. Thirty eight patients referred for hypertension underwent 24 h blood pressure monitoring. Echocardiography and repeated blood pressure measurements were taken on 2 different days by an observer and by the use of the Dinamap 845 device. Blood pressure by the observer averaged 157/101 mmHg, Dinamap pressure 152/94 mmHg, 24 h pressure 137/92 mmHg, left ventricular mass 218 g and mean wall thickness 12·7 mm. Left ventricular mass and wall thickness were related (P>0·05) to systolic observer (r=+ 0·46; r=+0·47), Dinamap (r=+0·42;r=+0·41) and 24 h bloodpressure (r=+0·46;r=+0·53); the correlation coefficients were lower (r=+03·5 to +0·51; P>0·05) for diastolic pressure. These relations were independent of age, gender, height, weight and heart rate. The Dinamap pressure did not contribute to the difference in the left ventricular structural characteristics, independent of the observer pressure. The 24 h ambulatory pressure explained a small but significant (P 0·25). In conclusion, observer, Dinamap and ambulatory pressures are significantly related to cardiac structural variables. Ambulatory pressure, but not Dinamap pressure, explains a small part of wall thickness variance in addition to well-standardized pressure measured by an observer.

Comparison of the effect of celiprolol and nifedipine on blood pressure and plasma lipids.

Abstract: During a double-blind, randomized study in hypertensive patients, changes in blood pressure (BP) and in plasma lipid and lipoprotein levels during treatment with celiprolol were compared with those occurring during nifedipine treatment. Fifty-three patients (28 men and 25 women) with mild-to-moderate hypertension, aged 20-64 years, were studied. After a 1-month placebo run-in period, patients were randomly assigned to receive either nifedipine (40 mg daily) or celiprolol (200 mg daily) each time using a double dummy technique. After 6 weeks, dosages of each drug could be doubled. Both drugs caused similar reductions in blood pressure but after 12 weeks treatment, the percentage of decrease in diastolic BP (DBP) was more pronounced (p less than 0.01) in the nifedipine group (-18%) than in the celiprolol group (-12%). After 6 weeks, there were no differences in plasma lipids between the two treatment groups. However, the changes after 12 weeks treatment were different (p less than 0.05) between the groups, leading to lower levels of plasma esterified cholesterol, low-density lipoprotein (LDL) cholesterol and apoprotein AI, AII, and B in the celiprolol group. Plasma lecithin cholesterol acyltransferase activity (LCAT) was not modified, suggesting that reverse cholesterol transport was not affected by the drugs. In both treatment groups, a significant positive relationship was observed between changes in LDL cholesterol and apoprotein B. As compared with nifedipine, celiprolol after 12-week therapy had a rather favorable plasma lipid profile. The clinical relevance of such findings, in terms of prevention of cardiovascular complications, has yet to be established.

Hypertensive heart disease: pathophysiology and clinical and prognostic consequences.

Abstract: The determinants of cardiac output were investigated in 161 patients with essential hypertension World Health Organization (WHO) stages I and II. In multiple regression analysis, cardiac output was inversely and independently related to blood pressure and to age. In patients with more severe hypertension, the lower cardiac output was associated with a lower stroke volume and a higher peripheral oxygen extraction. When age and blood pressure were taken into account, cardiac output was not a significant predictor of total mortality and of future cardiovascular events. Clinic and casual blood pressure explain only up to about 30% of the variability of echocardiographic left ventricular mass. The relationship of electrocardiographic voltages with blood pressure at various levels of bicycle exercise was highly significant in 169 patients with essential hypertension (r = 0.29-0.38; p less than 0.001) but the relationship was not better than with pressure at rest (r = 0.39). Ambulatory blood pressure, however, may be better related to left ventricular mass than clinic pressure. Several studies indicate that left ventricular hypertrophy is a significant risk factor for future cardiovascular events, independent of age and blood pressure. Left ventricular systolic function is usually normal in established hypertension, but diastolic function is frequently impaired, which could explain the reduced peak oxygen uptake in patients with more severe hypertension.

Effect of physical training on systemic and brachial artery haemodynamics in normal men.

Abstract: The effect of endurance training on resting systemic and brachial haemodynamics was studied in 27 normal sedentary volunteers using a randomized cross-over design. After four months of physical training, peak oxygen uptake and physical working capacity at a heart rate of 130 beats/min (PW130) were increased by 16% (p less than 0.01) and 29% (p less than 0.001), respectively. At end-diastole left ventricular wall thickness was increased (p less than 0.01), whereas internal diameter was not changed. However, the change in internal diameter was positively related (r = 0.44, p less than 0.036) to the change in PWC130, indicating that the internal diameter increased, particularly in those subjects with the greatest increase in exercise capacity. The systemic haemodynamic adaptation to training was characterized by an increased stroke volume and concomitant reduction in heart rate so that cardiac output was not changed. On the other hand, brachial blood flow decreased by 36% on average. The change in blood flow was negatively related (r = -0.43, p = 0.03) to the change in PWC130 after training. Half the number of subjects were restudied after a four-month detraining period. The echocardiographic and Doppler variables tended to return to the pretraining level.

Effects of baroceptor and cardiopulmonary reflexes on neural control of heart rate in normal man, as assessed by power spectral analysis.

Abstract: This study was designed to establish the neurally-mediated effects of baroceptor and cardiopulmonary reflexes on heart rate in normal subjects. We therefore studied the effects of various interventions, able to modify the activity of arterial baroreceptors and cardiopulmonary receptors, on the power spectrum of the R—R interval in nine healthy men. To confirm the efficacy of these interventions left ventricular volume was monitored using a portable radionuclide probe. Isosorbide dinitrate (5 mgm sublingually) while sitting unloads both baroreceptors and the cardiopulmonary receptors; it decreased left ventricular enddiastolic volume (p < 0.01) and the mean R—R interval (p < 0.005), increased the power of the low-frequency (LF) component of the R—R interval (p < 0.01), decreased the power of the high-frequency (HF) component (p < 0.005) and increased the LF/HF ratio (p < 0.05). The application of cuffs around the thighs in the supine position, which unloads only cardiopulmonary receptors, decreased left ventricular end-diastolic volume (p < 0.05) but did not affect mean R—R interval, LF component, HF component and LF/HF ratio (p ⩾ 0.10). Leg raising, which loads only cardiopulmonary receptors, increased left ventricular end-diastolic volume (p < 0.05) and did not affect the mean R—R interval, LF component, HF component and LF/HF ratio (p ≥ 0.10). In conclusion, our data suggest that, in normal man, baroreceptor unloading increased sympathetic and decreased parasympathetic neural control of heart rate; cardiopulmonary reflexes do not appear to have a direct neurally mediated effect on heart rate.

Trials in elderly patients with isolated systolic hypertension.

Abstract: The hypothesis that antihypertensive drugs should be prescribed to elderly patients with isolated systolic hypertension is being addressed in at least 3 trials: the Systolic Hypertension in the Elderly Program (SHEP) in the United States, a trial in China, and the Syst-Eur study in Europe. The SHEP trial has recently reported its final morbidity and mortality results. This article summarizes the protocol of the European study. To be eligible for the Syst-Eur trial, patients must be at least 60 years old and have a systolic blood pressure averaging 160-219 mmHg with a diastolic pressure less than 95 mmHg. Patients must give their informed consent and be free of major cardiovascular and non-cardiovascular diseases at entry. The patients are randomized into active treatment or placebo. Active treatment consists of nitrendipine (10-40 mg/d), combined with enalapril (5-20 mg/d) and hydrochlorothiazide (12.5-25 mg/d), as necessary. The control group received matching placebos. The drugs (or matching placebos) are stepwise titrated and combined in order to reduce systolic blood pressure by 20 mmHg at least to a level below 150 mmHg. Morbidity and mortality are monitored to enable an intention-to-treat and per protocol comparison of the outcome in the two treatment groups.

Treatment of the older hypertensive: paradigms, practices, and proofs.

Abstract: Recent outcome trials in patients above age 60 with systolo-diastolic hypertension are reviewed. The metaanalysis suggests that antihypertensive drug therapy can decrease cardiovascular and coronary mortality in selected patients. Based on these studies it is suggested that antihypertensive drug therapy is indicated in patients between age 60 and 75 when the diastolic pressure remains above 95 mmHg after repeated measurements. A target for systolic b.p. is not definitely established but a pressure of 150 mmHg may serve as a temporary proposal. Whether uncomplicated isolated systolic hypertension in symptomless patients should be treated is still under investigation.