Beta-Blocker Use After Acute Myocardial Infarction: Differential Impact Across Heart Failure Subtypes in a Real-World Cohort.

BACKGROUND: Beta-blocker (BB) benefits after acute myocardial infarction (AMI) may differ by heart failure (HF) phenotype in the contemporary reperfusion era. OBJECTIVES: The authors evaluated associations of in-hospital BB therapy with 1-year outcomes after AMI complicated by HF, stratified by left ventricular ejection fraction phenotype. METHODS: We analyzed 5,557 patients with AMI complicated by HF from the Tianjin Coronary Artery Disease Specialized Database, including 3,962/5,557 (71.3%) with HF with preserved ejection fraction (HFpEF) and 1,595/5,557 (28.7%) with HF with reduced or mildly reduced ejection fraction (HFrEF/HFmrEF). The primary endpoint was a 1-year composite of cardiac death or HF rehospitalization. We assessed associations using inverse probability of treatment weighting, Cox models, and competing risk analyses. Sensitivity analyses comprised propensity score matching, win ratio, and time-stratified Cox models. RESULTS: Overall, 859/5,557 patients (15.5%; 95% CI: 14.5%-16.4%) reached the primary endpoint by 1 year; median follow-up was 1,566 days (IQR: 882-2,354). Interaction by HF phenotype was significant (P = 0.034). After adjustment, BB therapy was associated with lower primary endpoint risk in HFrEF/HFmrEF (adjusted HR [aHR]: 0.590; 95% CI: 0.438-0.795; P < 0.001), but not in HFpEF. BB therapy was also associated with lower risks of all-cause death (aHR: 0.577; 95% CI: 0.395-0.841; P = 0.004) and cardiac death (aHR: 0.536; 95% CI: 0.349-0.823; P = 0.004) in HFrEF/HFmrEF. Sensitivity analyses yielded consistent findings. CONCLUSIONS: Among patients with AMI complicated by HF, in-hospital BB use was associated with lower 1-year adverse outcomes risk in HFrEF/HFmrEF, but not in HFpEF.