Follow-up study of patients randomly allocated ramipril or placebo for heart failure after acute myocardial infarction: AIRE Extension (AIREX) Study. Acute Infarction Ramipril Efficacy

Abstract

Background: In the Acute Infarction Ramipril Efficacy (AIRE) Study, the effect of angiotensin-converting-enzyme (ACE) inhibition on the survival of patients with clinical heart failure after acute myocardial infarction (AMI), was assessed. At an average follow-up time of 15 months after randomisation, all-cause mortality was reduced from 22.6% (placebo group) to 16.9% (ramipril group) representing an absolute mortality reduction of 5.7% and a relative risk reduction of 27% (95% CI 11-40%; p = 0.002). Our aim in this study was to assess the long-term (3 years after the AIRE Study closed) magnitude, duration, and reliability of the survival benefits observed after treatment with ramipril (target dose 5 mg twice a day) when compared with placebo.

Methods: We investigated the mortality status of all 603 patients recruited from the 30 UK centres involved in the AIRE Study. Through government records we were able to confirm the death or survival of all 603 patients exactly 3 years after the close of the AIRE Study. Follow-up was for a minimum of 42 months and a mean of 59 months. The average duration of treatment with masked trial medication was 13.4 months for placebo and 12.4 months for ramipril.

Findings: By 0000 h March 1, 1996, death from all causes had occurred in 117 (38.9%) of 301 patients randomly assigned placebo and 83 (27.5%) of 302 patients randomly assigned ramipril, representing a relative risk reduction of 36% (95% CI 15-52%; p = 0.002) and an absolute reduction in mortality of 11.4% (114 additional 5-year survivors per 1000 patients treated for an average of 12.4 months).

Interpretation: Our data provide robust evidence that administration of ramipril to patients with clinically defined heart failure after AMI results in a survival benefit that is not only large in magnitude, but also sustained over many years.