Effect of Angiotensin-converting enzyme inhibition on one-year mortality and frequency of repeat acute myocardial infarction in patients with acute myocardial infarction.

Controversy exists regarding whether all patients with acute myocardial infarction (AMI) benefit from angiotensin-converting enzyme inhibitors (ACEIs). We examined the association between ACEI treatment and mortality in a large, unselected population of patients with AMI. The present study included 105,224 patients with AMI who were not treated with ACEIs on admission. A logistic regression analysis, including 33 variables, calculated a propensity score for each patient to estimate the probability of receiving ACEIs at discharge, given the background. The association between ACEI treatment at discharge and the 1-year outcome was evaluated in prespecified subgroups using the Cox regression analyses, adjusting for the propensity score and medications at discharge. A total of 38,395 patients (36.5%) received ACEIs at discharge. After adjustment, ACEI treatment was associated with a 24% reduction in mortality (relative risk 0.76, 95% confidence interval 0.73 to 0.80). The benefit was largest in patients with a history or present signs of heart failure. In patients without heart failure, a significant benefit of ACEI treatment was seen only in patients with renal dysfunction (relative risk 0.69, 95% confidence interval 0.54 to 0.88). In the whole group, the risk of AMI decreased by 7% (relative risk 0.93, 95% confidence interval 0.90 to 0.96), with a larger effect seen in patients with ST-segment elevation AMI or systolic left ventricular dysfunction. In conclusion, in unselected patients with AMI, ACEI treatment was associated with a reduction in 1-year mortality, mainly in patients with heart failure or renal dysfunction, and a small reduction in the risk of reinfarction, mainly in patients with ST-segment elevation AMI or systolic left ventricular dysfunction.