Cost-effectiveness of captopril therapy after myocardial infarction

OBJECTIVES: This study sought to assess the cost-effectiveness of captopril therapy for survivors of myocardial infarction. BACKGROUND: The recent randomized, controlled Survival and Ventricular Enlargement (SAVE) trial showed that captopril therapy improves survival in survivors of myocardial infarction with an ejection fraction < or = 40%. The present ancillary study was designed to determine how the costs required to achieve this increase in survival compared with those of other medical interventions. METHODS: We developed a decision-analytic model to assess the cost-effectiveness of captopril therapy in 50- to 80-year old survivors of myocardial infarction with an ejection fraction < or = 40%. Data on costs, utilities (health-related quality of life weights) and 4-year survival were obtained directly from the SAVE trial, and long-term survival was estimated using a Markov model. In one set of analyses, we assumed that the survival benefit associated with captopril therapy would persist beyond 4 years (persistent-benefit analyses), whereas in another set we assumed that captopril therapy incurred costs but no survival benefit beyond 4 years (limited-benefit analyses). RESULTS: In the limited-benefit analyses, the incremental cost-effectiveness of captopril therapy ranged from 3, 600/quality-adjusted life-year for 80-year old patients to 60, 800/quality-adjusted life-year for 50-year old patients. In the persistent-benefit analyses, incremental cost-effectiveness ratios ranged from 3, 700 to 10, 400/quality-adjusted life-year, depending on age. The outcome was generally not sensitive to changes in estimates of variables when they were varied individually over wide ranges. In a "worst-case" analysis, incremental cost-effectiveness ratios for captopril therapy remained favorable (8, 700 to 29, 200/quality-adjusted life-year) for 60- to 80-year old patients but were higher (217, 600/quality-adjusted life-year) for 50-year old patients. CONCLUSIONS: We conclude that the cost-effectiveness of captopril therapy for 50- to 80-year old survivors of myocardial infarction with a low ejection fraction compares favorably with other interventions for survivors of myocardial infarction.