LAUSR

In the era of the initial optimal interventional and medical therapy for acute myocardial infarction (AMI), a number of patients with mildly reduced left ventricular ejection fraction (EF) (41 - 49%) have been increasing. This observational study aimed to investigate the association between the medical therapy with oral beta-blockers or inhibitors of renin-angiotensin system (RAS) and 2-year clinical outcomes in patients with mildly reduced EF after AMI. Among patients enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health, propensity-score matched patients who survived the initial attack and had mildly reduced EF were selected according to beta-blocker or RAS inhibitor therapy at discharge. Beta-blocker therapy at discharge was associated with lower 2-year major adverse cardiac events which was a composite of cardiac death, myocardial infarction, revascularization and re-hospitalization due to heart failure (8.7 vs. 12.8/100 patient-years; hazard ratio [HR] 0.68; 95% confidence interval [CI] 0.50-0.93; P =0.015), and no significant interaction between EF [≤]45% and >45% was observed ( P interaction =0.354). This association was mainly driven by lower myocardial infarction in patients with beta-blockers (HR 0.50; 95% CI 0.26-0.95; P =0.035). Inhibitors of RAS at discharge were associated with lower re-hospitalization due to heart failure (1.8 vs. 3.5/100 patient-years; HR 0.53; 95% CI 0.33-0.86; P =0.010) without a significant interaction between EF [≤]45% and >45% ( P interaction =0.333). In patients with mildly reduced EF after AMI, the medical therapy with beta-blockers or RAS inhibitors at discharge was associated with better 2-year clinical outcomes.