Effects of antihypertensive treatment on coronary artery disease: Directions for future research

Previous trials have shown that a 5-6 mm Hg reduction in diastolic blood pressure produced by anti-hypertensive treatment (mainly diuretics) reduces the risk of coronary artery disease (CAD) by 14% SD5 (2p < 0.01). However, the 95% confidence limits for this estimate of treatment effect are wide and consistent, with true reductions as small as 4% or as large as 22%. For this reason, it is not possible to determine whether the treatment benefit is of a worthwhile magnitude. Because CAD remains the leading cause of death in hypertensive patients (and normolensive patients) in most Western populations, further studies are required to determine more precisely the effect of blood pressure reduction on the incidence of CAD. This could be achieved by further large-scale studies comparing antihypertensive treatment with no treatment. It could also be achieved by comparing the effects of more and less intensive antihypertensive treatment regimens. Additional relevant information might also be generated by studies comparing the effects on CAD of new classes of antihypertensive drugs (such as angiotensin-converting enzyme inhibitors and calcium antagonists) with those of older classes (in particular diuretics.). In all such studies, the detection of plausible treatment effects or of plausihle treatment differences requires the recruitment of large study-populations with follow-up continued for several years. This is only feasible if study methods are kept simple to insure the widest possible collaboration. © 1991 Raven Press, Ltd., New York.