Antoon Amery

Isolated systolic hypertension in the elderly

Isolated systolic hypertension affects between 10 and 20% of the elderly. The growing awareness among physicians and patients that systolic hypertension carries a risk, which is greater in the elderly than that of diastolic blood pressure elevation, has sparked many questions on the prevalence, pathophysiology and treatment of isolated systolic hypertension. This paper reviews published studies on isolated systolic hypertension in the elderly

The influence of menopause on blood pressure

The association between menopause and systolic and diastolic blood pressure was explored in a random sample of 278 pre- and 184 post-menopausal women. In 64 subjects menopause had been surgically induced. Post-menopausal women had a higher systolic, diastolic and pulse pressure than pre-menopausal subjects (P less than 0.001). Hypertension, defined as being on antihypertensive medication, regardless of BP, or as having a pressure greater than or equal to 140/90 mmHg, was more frequently observed following menopause (40 vs 10%; P less than 0.001). After stratification by age and body mass index, the odds of having hypertension for pre- as compared with post-menopausal women were 2.2 (95% confidence interval from 1.1 to 4.4; P = 0.03). After adjustment of BP for significant covariates, such as body mass index, pulse rate and contraceptive pill intake, the slope of SBP on age was 0.5 mmHg/year (P less than 0.05) steeper in women with natural and surgical menopause than in pre-menopausal subjects. The relation of DBP with age showed a similar slope among pre- and post-menopausal subjects, but in women with natural and surgical menopause taken together, the regression line was shifted upward by an average of 2.3 mmHg (P = 0.03). The relationships of DBP with body mass index and with the urinary sodium: potassium ratio were also 0.2 mmHg/kg/m2 and 0.8 mmHg/unit steeper (P less than 0.05) in post- than in pre-menopausal subjects. In conclusion, in the present cross-sectional study menopause was accompanied by a steeper rise of SBP with age, and by an increase in the absolute level of DBP, which was independent of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Impairment of Renal Function with Increasing Blood Lead Concentrations in the General Population

BACKGROUND Nephropathy is known to occur in persons with heavy exposure to lead. Whether exposure to lead in the general population leads to impaired renal function is not known. METHODS We studied renal function and indexes of lead exposure in a random population sample of 965 men and 1016 women (age range, 20 to 88 years). In all the subjects we measured creatinine clearance and blood concentrations of lead and zinc protoporphyrin (an indirect measure of blood lead level). RESULTS The mean (+/- SD) creatinine clearance rate was 99 +/- 30 ml per minute in the men and 80 +/- 25 ml per minute in the women. In the men the geometric mean blood lead concentration was 114 micrograms per liter (0.55 mumol per liter) (range, 23 to 725 micrograms per liter [0.11 to 3.5 mumol per liter]), and in the women 75 micrograms per liter (0.36 mumol per liter) (range, 17 to 603 micrograms per liter [0.08 to 2.9 mumol per liter]); the zinc protoporphyrin values in blood averaged 1.0 and 1.1 micrograms per gram of hemoglobin, respectively. The creatinine clearance rate was inversely correlated with blood lead and zinc protoporphyrin values in the men and the women both before and after adjustments for age, bodymass index, and diuretic treatment. A 10-fold increase in blood lead concentration was associated with a reduction of 10 to 13 ml per minute in creatinine clearance. We also found a positive correlation between serum beta 2-microglobulin (which is inversely related to the glomerular filtration rate) and blood lead in men, between serum beta 2-microglobulin and zinc protoporphyrin in both sexes, and between serum creatinine and zinc protoporphyrin in men. CONCLUSIONS Exposure to lead may impair renal function in the general population. The alternative hypothesis that renal impairment may lead to an increase in the blood lead concentration cannot be excluded, however.

Mean and range of the ambulatory pressure in normotensive subjects from a meta-analysis of 23 studies

To perform a meta-analysis of published reports in an attempt to determine the mean and range of normal ambulatory blood pressure (BP), 23 studies including a total of 3,476 normal subjects were reviewed. Most studies were compatible with a mean 24-hour BP in the range of 115 to 120/70 to 75 mm Hg, a mean daytime BP of 120 to 125/75 to 80 mm Hg, and a mean nighttime BP of 105 to 110/60 to 65 mm Hg. With weighting for the number of subjects included in the individual studies, the 24-hour BP averaged 118/72 mm Hg, the daytime BP 123/76 mm Hg, and the nighttime BP 106/64 mm Hg. The night/day pressure ratio averaged 0.87 for systolic and 0.83 for diastolic BP, with ranges across the individual studies from 0.79 to 0.92 and from 0.75 to 0.90, respectively. If the mean +/- 2 standard deviation interval in the various studies was considered normal, the range of normality was on average 97 to 139/57 to 87 mm Hg for the 24-hour BP, 101 to 146/61 to 91 mm Hg for the daytime BP, and 86 to 127/48 to 79 mm Hg for the nighttime BP. Until the results of prospective studies on the relation between the ambulatory BP and the incidence of cardiovascular morbidity and mortality become available, the aforementioned intervals, which summarize the experience of 23 investigators, could serve as a temporary reference for clinical practice.

Prognostic significance of peak exercise capacity in patients with coronary artery disease

OBJECTIVES The aim of this study was to investigate the prognostic significance of peak oxygen uptake in patients with coronary artery disease who had an exercise test that could be sustained to exhaustion without limiting symptoms. BACKGROUND Many studies have reported an inverse association between the level of exercise reached during a stress test and mortality or cardiovascular morbidity. These studies have used submaximal or symptom-limited exercise testing in patients with a recent myocardial infarction. METHODS Peak oxygen uptake was measured in male patients > or = 4 weeks after myocardial infarction (312 patients) or coronary artery surgery (215 patients) by use of a graded uninterrupted exercise test performed to exhaustion. Apart from peak oxygen uptake, several risk factors for cardiovascular disease, patient and exercise characteristics and drug treatment were considered in the Cox proportional hazards model. RESULTS During the total follow-up period of 3,213 patient-years, 53 patients died. Of these 53 patients, 33 died of cardiovascular causes. All-cause and cardiovascular mortality decreased with increasing peak oxygen uptake, even after adjustment for significant covariates. The relative hazard rates of 0.43 and 0.29 indicate that a hypothetic increase in peak oxygen uptake by 1 liter/min could be associated with decreases in all-cause and cardiovascular mortality of 57% and 71%, respectively. CONCLUSIONS Exercise capacity is an independent predictor for subsequent all-cause and cardiovascular mortality in patients able to perform an exercise test until exhaustion.

Noninvasive assessment of seasonal variations in cardiac structure and function in cyclists.

Noninvasive studies were performed in 12 male bicylists in the competitive season (CS) and in the resting season (RS) and in 12 matched control subjects to determine seasonal variations in cardiac structure and function in athletes and to compare the data with those of nonathletes. In athletes, peak oxygen uptake was 6% lower in the RS than the CS; the RS value was 40% higher than in nonathletes. The echocardiograms of athletes showed a higher left ventricular total diameter at end-diastole in the CS than in the RS; this difference was due to a greater septal and posterior wall thickness, with unchanged internal diameter. On the ECG, R-wave voltages were larger in the CS in leads I, V5 and V6. Athletes had greater left ventricular dimension and wall thickness than nonathletes, and their ratio of wall thickness to internal radius of the left ventricle was higher. Various echo- and mechanocardiographic indexes of left ventricular function were determined. During the RS, the athletes had a lower percent shortening and maximal velocity of left ventricular internal diameter, lower maximal and minimal velocities of the endocardium of the posterior wall, a longer preejection period and a larger ratio of preejection period to left ventricular ejection time. These findings are probably related to a greater left ventricular end-systolic stress, an index of myocardial afterload, in the RS.We conclude that cyclists in the CS, compared with nonathletes, have greater left ventricular internal dimension and increased wall thickness, with similar left ventricular function. During the RS, internal dimension does not change from the level in the CS, but wall thickness is somewhat reduced and left ventricular function is slightly depressed, most likely because of a higher afterload in RS.

Prognostic value of training-induced change in peak exercise capacity in patients with myocardial infarcts and patients with coronary bypass surgery

An inverse association between mortality and exercise capacity has been demonstrated previously in patients with coronary artery disease. Physical training generally increases exercise capacity. Only 1 study investigated the prognostic value of exercise capacity after training, but only in a limited number of patients. No data are available on the relation between mortality and the change in exercise performance with training. Peak oxygen uptake (VO2) was measured before and after a 3-month, predominantly dynamic training period in 417 patients with coronary artery disease. Apart from peak VO2, several patient characteristics, risk factors for cardiovascular disease, and exercise data were considered in a Cox proportional-hazards model. Peak VO2 had increased by 33% after the training period. During the total follow-up of 2,583 patient-years, 37 patients died. The cause of death was cardiovascular in 21. The prognostic value of peak VO2 was higher after training than before training, even after adjustment for age and other significant covariates. Cardiovascular mortality decreased more with greater increases in peak VO2 after training. The relative hazard rate of 0.98 indicates that a 1% greater increase in peak VO2 after training would be associated with a decrease in cardiovascular mortality of 2%. No differences in prognostic value and in training effects were observed between patients with myocardial infarcts and patients after coronary bypass grafting. Peak VO2, evaluated after a physical training program, and its change in response to training are independent predictors for cardiovascular mortality in patients with coronary artery disease.

A Consensus View on the Technique of Ambulatory Blood Pressure Monitoring

This review, based on the Fourth International Consensus Conference on Ambulatory Blood Pressure Monitoring (Leuven, Belgium, 1994), deals with the technical aspects of ambulatory blood pressure monitoring. Ambulatory blood pressure monitoring by noninvasive intermittent techniques is widely used despite artifacts due to cuff size, movement, body position, short-term blood pressure variability, and interference with sleep. The performance of the currently available monitors under truly ambulatory conditions and during exercise remains a matter of debate, as are the procedures required to validate portable monitors under these circumstances. There is general agreement that whenever a monitor is to be used in special populations, such as older subjects or pregnant women, or in special conditions, such as exercise, a specific demonstration of its accuracy in these defined subgroups or conditions is warranted. Whether the auscultatory or oscillometric method is preferred remains controversial because each technique has specific advantages and disadvantages and because both can provide accurate results. Most experts in the field strongly believe that manufacturers should disclose the algorithms of their devices and that they should specify all changes made to the hardware and software of a previously validated monitor. Finally, the development of the volume-clamp method, which makes continuous noninvasive registration of blood pressure at the finger possible in both stationary and ambulatory conditions, opens new perspectives in research, in particular in relation to short-term blood pressure variability.

Ambulatory blood pressure in normotensive and hypertensive subjects: Results from an international database

Objective To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement. Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (CBP 140/90 mmHg), 719 were borderline hypertensive (systolic CBP 141–159 mmHg or diastolic CBP 91–94 mmHg) and 1773 were definitely hypertensive. Of the subjects in the last of these categories, 1324 had systolic hypertension (systolic CBP 21 60 mmHg) and 131 0 had diastolic hypertension (diastolic CBP 295 mmHg). Combined systolic and diastolic hypertension was present in 861 subjects. Hypertension had been diagnosed from the mean of two to nine (median two) CBP measurements obtained at one to three (median two) visits. Results The 95th centiles of the ABP distributions in the normotensive subjects were (systolic and diastolic, respectively) 133 and 82 mmHg for 24-h ABP, 140 and 88mmHg for daytime ABP and 125 and 76mmHg for night-time ABP, respectively. Of the subjects with systolic hypertension, 24% had 24-h systolic ABP 4 33 mmHg. Similarly, 30% of those with diastolic hypertension had 24-h diastolic ABP 432 mmHg. The probability that hypertensive subjects had 24-h ABP below these thresholds tended to increase with age and was two- to fourfold greater if the CBP of the subject had been measured at only one visit and if fewer than three CBP measurements had been averaged for establishing the diagnosis of hypertension. By contrast, for each 1 O-mmHg increment in systolic CBP, this probability decreased by 54% for 24-h systolic ABP and by 26% for 24-h diastolic ABP, and for each 5-mmHg increment in diastolic CBP it decreased by 6 and 9%, respectively. In comparison with 24-h ABP, the overlap in the daytime and night-time ABP between normotensive and hypertensive subjects was of similar magnitude and was influenced by the same factors. Conclusions The ABP distributions of the normotensive subjects included in the present international database were not materially different from those in previous reports in the literature. One-fifth to more than one-third of hypertensive subjects had an ABP which was below the 95th centile of the ABP of normotensive subjects, but this proportion decreased if the hypertensive subjects had shown a higher CBP upon repeated measurement. The prognostic implications of elevated CBP in the presence of normal ABP remain to be determined.

Syst-Eur. A multicentre trial on the treatment of isolated systolic hypertension in the elderly: Objectives, protocol, and organization

SummaryThe Syst-Eur Trial is a concerted action of the European Community’s Medical and Health Research Programme. The trial is carried out in consultation with the World Health Organization, the International Society of Hypertension, the European Society of Hypertension and the World Hypertension League. This article describes the objectives and the protocol of Syst-Eur, a multicentre trial designed by the European Working Party on High Blood. Pressure in the Elderly (EWPHE), to test the hypothesis that antihypertensive treatment of elderly patients with isolated systolic hypertension results in a significant change in stroke morbidity and mortality. Secondary endpoints include cardiovascular events, such as myocardial infarction and congestive heart failure.To be eligible 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 to active treatment or placebo. Active treatment consists of nitrendipine (10–40 mg/day), combined with enalapril (5–20 mg/day) and hydrochlorothiazide (12.5–25 mg/day), as necessary. The patients of the control group receive 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 perprotocol comparison of the outcome in the 2 treatment groups.A one-year pilot trial (1989) showed that the protocol is practicable. The Ethics Committee therefore decided to start the definite study (1990), in which randomized patients will be followed for 5 years. Recruitment of new centres and of the required 3,000 patients will last 3 years (until 1993).