Angiotensin-converting enzyme inhibitors and coronary heart disease prevention.

A number of large randomised controlled trials have shown that angiotensin-converting enzyme (ACE) inhibitors, compared with placebo or other blood pressure-lowering drugs, improve coronary heart disease outcomes (fatal and non-fatal myocardial infarction, and coronary revascularisation) in diverse patient groups, e.g. in primary and secondary prevention, those with and without left ventricular dysfunction, and among hypertensive and non-hypertensive subjects. An updated meta-regression analysis which included five major trials in patients with established coronary artery disease (CAD) (EUROPA, INVEST, ACTION, PEACE and CAMELOT) concluded that ACE inhibitor (ACE-I) therapy has clear benefits in secondary prevention, but there are important and unexplained differences between trials in clinical outcome, baseline cardiovascular risk, blood pressure changes and trial design which deserve further discussion of the underlying mechanisms and clinical interpretation. For example, in placebo-controlled trials the biggest (2022%) reductions in primary end points (including mortality) have been observed with perindopril and ramipril, whereas trials using trandolapril and quinapril had no effect on survival or recurrent CAD events. This review summarises and compares the major findings of these recent trials, and provides further analysis of the underlying mechanisms and clinical significance of secondary CAD prevention with ACE-I therapy.