OBJECTIVES: To assess, from a societal perspective, the cost-effectiveness of use of ramipril (Altace(r)) after invasive revascularization, based on the Angiotensin-converting Enzyme Inhibition Post Revascularization Study (APRES), which found that ramipril was associated with significantly reduced risk of cardiac mortality and of non-fatal events. METHODS: Probabilities of acute myocardial infarction (AMI), congestive heart failure (CHF), angina pectoris and cardiac mortality associated with ramipril or placebo from APRES, a randomized, double-blind, placebo-controlled study of 159 patients who had undergone revascularization were applied to a decision-analytic model. Reduction in risk of non-fatal events was used to model expected costs and reduction in risk of cardiac mortality was used to define effectiveness. Unit costs were based on hospitalization charges from the 1997 Healthcare Cost and Utilization Project (HCUP-3), adjusted by the Medicare cost-to-charge ratio, as well as costs obtained from published literature. Drug costs were based on published average wholesale prices (AWP) from the 1997 Red Book. All costs were discounted at 3% per year. RESULTS: Based on average daily AWP of $0.94, ramipril was associated with a discounted incremental cost of $934 per patient over 33 months of treatment and, after accounting for cost offsets due to reduced risk of clinical events, a net expected incremental cost per patient of $327. Given a 7.6% absolute risk reduction in cardiac mortality (8.9% less 1.3%, p<0.05), ramipril was associated with an incremental expected cost of $4,300 per death averted and, correspondingly, $371 per life year saved, based on additional life expectancy in this patient population. Sensitivity analysis indicated that these estimates ranged from a total cost offset (minus $61 per life year saved) in the best scenario to $861 per life year saved in the worst scenario. CONCLUSIONS: Ramipril is expected to be a cost-effective addition to medical management of patients undergoing revascularization.