Association of beta-blockers or inhibitors of renin-angiotensin system with clinical outcomes in patients with mid-range left ventricular ejection fraction after acute myocardial infarction

Abstract

Abstract Background In the era of the initial optimal interventional and medical therapy for acute myocardial infarction (AMI), a number of patients with mid-range left ventricular ejection fraction (EF) (>40%, <50%) becomes increasing. Purpose This observational study aimed to investigate the association between oral beta-blockers or inhibitors of renin-angiotensin system (RAS) and 2-year clinical outcomes in patients with mid-range EF after AMI. Methods Among 13,624 patients enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH), propensity-score matched patients who survived the initial attack and had mid-range EF were selected according to beta-blocker or RAS inhibitor therapy at discharge. Results Beta-blocker therapy at discharge was associated with lower 2-year major adverse cardiac events (MACE) of cardiac death, MI, revascularization or re-hospitalization due to heart failure (8.7 vs. 12.8/100 person-year; 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 for interaction=0.354). This association was mainly driven by lower MI in patients with beta-blockers (1.6 vs. 3.1/100 person-year; HR 0.50; 95% CI 0.26–0.95; P=0.035). Inhibitors of RAS at discharge were not associated with lower 2-year MACE, but with lower re-hospitalization due to heart failure (1.8 vs. 3.5/100 person-year; HR 0.53; 95% CI 0.33–0.86; P=0.010) without significant interaction between EF ≤45% and >45% (P for interaction=0.333). Conclusions Beta-blockers or RAS inhibitors at discharge were associated with better 2-year clinical outcomes without significant interaction between ≤45% and >45% in patients with mid-range EF after AMI.</ef<50%)> Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korea Centers for Disease Control and Prevention. 2-year clinical outcomes