BACKGROUND: Angiotensin converting enzyme-inhibitors (ACEI) and angiotensin-II-receptor blockers (ARB) are equally efficacious in reducing mortality after MI, although the latter are far more costly. Little is known about their relative use after MI in typical care settings, and about their relative effectiveness outside the clinical trial setting.
OBJECTIVES: To assess temporal trends in the relative use of ACEI and ARB after myocardial infarction, and to test for differences in 1-year survival between users of these drug classes.
DESIGN: Retrospective closed cohort study.
PATIENTS: Medicare beneficiaries who survived >90 days after myocardial infarction, had full prescription drug coverage, and who filled a prescription for either ACEI or ARB within 90 days of myocardial infarction.
MEASUREMENTS: Relative use of ACEI versus ARB over time. Adjusted relative 1-year mortality between ACEI and ARB users.
RESULTS: Between 1995 and 2004, 14,190 patients met inclusion criteria. Mean age was 80 years, 75% were female, and 90% were white. Overall, 88% received an ACEI, and 12% an ARB, with the proportion receiving an ARB increasing from 2% (1995) to 25% (2004; P<.001). Multivariate-adjusted 1-year mortality did not differ between ARB and ACEI users (HR: 1.04; 95% confidence interval: 0.88 to 1.22). The findings were similar for new users of ACEI/ARB, and for those with preexisting heart failure.
CONCLUSIONS: ARB users had the same 1-year mortality after myocardial infarction as ACEI users in routine care. Use of more costly ARB has increased dramatically over time, to a quarter of ACEI/ARB users, despite the lack of a therapeutic advantage for most patients.