Clinical implications for the Acute Infarction Ramipril Efficacy extension (AIREX) Study

It is now clear that angiotensin-converting enzyme (ACE) inhibitor treatment after myocardial infarction (MI) reduces mortality and morbidity. However, the benefits of ACE inhibition are not homogeneous and are largely confined to high-risk patients who have subjective or objective evidence of left ventricular (LV) dysfunction. How long treatment should continue is a vexed question, which also arises with other agents, for example beta-blocker use after MI. The AIREX study assessed the long-term magnitude and duration of the survival benefits observed with ramipril in patients after MI who have clinically defined heart failure. The mortality status of all 603 patients recruited from the UK centres involved in the AIRE study was verified at an extended 5-year follow-up (3 years after the AIRE study closed). Ramipril assignation was associated with a 36% relative and a 11% absolute mortality risk reduction. These findings strongly support the view to select patients on the basis of impaired LV function and reinforce the previously reported conclusions of the "selective" ACE inhibition post-MI trials. Using this approach, the survival benefit is not only of large magnitude but also sustained over many years. These results also argue for life-long treatment with an ACE inhibitor, once a decision to treat an individual patient after MI has been made.