Acute administration of angiotensin converting enzyme inhibitors in thrombolysed myocardial infarction patients is associated with a decreased incidence of heart failure, but an increased re-infarction risk

Ventricular remodeling starts very early after the onset of an acute myocardial infarction (AMI), and can be prevented by ACE-inhibitors. However, very limited data are available on the effect of acute (< 9 hours) treatment with angiotensin converting enzyme (ACE) inhibitors after an AMI on mortality, heart failure and re-infarction. The aim of the present study was to evaluate the effects of acute ACE-inhibitor treatment. We performed a pooled analysis of three very similar randomized, placebo-controlled multi-center trials. In 845 thrombolysed patients with mainly first anterior MI, patients were randomised to acute ACE-inhibitor treatment (< 9 hours after MI) or placebo. After acute ACE-inhibitor treatment we observed similar 3-months mortality rates, and a significant reduction in the incidence of 3-months heart failure (26.1 vs. 19.3%; RR 0.67; 95% CI 0.45-1.0) as compared to placebo. In contrast, acute ACE-inhibitor treatment was associated with a significant 2.0 times increased 3-months re-infarction risk (7.0 vs. 3.6%; RR 2.0; 95% CI 1.1 to 3.8). Subgroup-analysis showed that patients with small infarct sizes treated with acute ACE-inhibitor (peak CPK < 1000 IU) had a 7.6 times higher re-infarction risk (95% CI 1.7 to 33) than patients with small infarctions treated with placebo. Acute ACE-inhibitor treatment in thrombolysed patients with mainly first anterior AMI resulted in a reduction of heart failure and similar mortality, but an increase in re-infarction rates, especially in patients with small infarct sizes. These results warrant caution for the very early use of ACE-inhibitors in smaller infarctions, although this needs to be confirmed in a larger prospective randomised clinical trial.