Beta-blockade in the primary prevention of coronary heart disease in hypertensive patients. Review of present evidence

Abstract

The aim of this review is to present an overview of the results of randomized primary preventive trials with beta-blockers in patients with hypertension. For statistical and biological reasons, any preventive effect on coronary events is hard to demonstrate in women in these primary preventive trials because of the low incidence of coronary events in middle-aged, white women. Therefore, special attention will be focused on the effect in men. Four beta-blockers have been studied: propranolol, oxprenolol, atenolol, and metoprolol. Results from the Metoprolol Atherosclerosis Prevention in Hypertensives (MAPHY) trial showed that the risk for coronary events was 24% lower in patients receiving beta-blockade compared with patients receiving diuretics (p less than 0.001). In men, three beta-blockers (propranolol, oxprenolol, and metoprolol) have shown significantly lower risk for coronary events (fatal and nonfatal) in the nonsmoking subgroup. Results from the MAPHY study also indicated a reduction in total and coronary mortality with the beta-blocker as compared with thiazide diuretics. The observed reduced risk for coronary events with beta-blockers as compared with diuretics is probably independent of the reduction in blood pressure. Mechanisms currently under study include antiatherosclerotic effects, antithrombotic effects, anti-ischemic effects, and antifibrillatory effects. It is not possible to judge, with present evidence, if all beta-blockers are equally effective in preventing sudden death and other coronary events.