Diuretic agents versus beta-blockers. Comparison of effects on mortality, stroke, and coronary events

Three recently concluded large randomized clinical trials have compared the preventive effects of diuretic agents and beta-blockers in the treatment of approximately 22,000 subjects with hypertension. In the Medical Research Council trial, bendrofluazide (10 mg daily) was compared with a dose of propranolol (as much as 240 mg daily), a nonselective beta-blocker without intrinsic sympathomimetic activity. Two selective beta-blockers, atenolol (100 mg daily) and metoprolol (200 mg daily), were compared with bendrofluazide (5-10 mg daily) and hydrochlorothiazide (50-100 mg daily) in the Heart Attack Primary Prevention in Hypertension trial. In the International Prospective Primary Prevention Study in Hypertension, 160 mg of slow-release oxprenolol, a beta-blocker with intrinsic sympathomimetic activity, was compared with a diuretic-based regimen not containing beta-blockers. In each trial, similar reductions in mean diastolic blood pressure were achieved with diuretic and beta-blocker treatment that lasted for several years. All-cause mortality and fatal and nonfatal stroke and coronary event rates were also similar in the treatment groups. Thus, it appears that beta-blockers are as effective as diuretic agents in improving survival and in preventing major morbid events. Regarding cigarette smoking and stroke incidence, observations based on post hoc subgroup analyses of the Medical Research Council trial were not supported by subgroup findings in the Heart Attack Primary Prevention in Hypertension and the International Prospective Primary Prevention Study in Hypertension trials, and these observations should not form the basis for any treatment recommendations.