LAUSR

Background There are limited data available on the impact of early (within 24 h of admission) β-blocker therapy on in-hospital outcomes of patients with ST-elevation myocardial infarction (STEMI) and mild-moderate acute heart failure. This study aimed to explore the association between early oral β-blocker therapy and in-hospital outcomes. Methods Inpatients with STEMI and Killip class II or III heart failure from the Improving Care for Cardiovascular Disease in China project (n = 10,239) were enrolled. The primary outcome was a combined endpoint composed of in-hospital all-cause mortality, successful cardiopulmonary resuscitation after cardiac arrest, and cardiogenic shock. Inverse-probability-of-treatment weighting, multivariate Cox regression, and propensity score matching were performed. Results Early oral β-blocker therapy was administered to 56.5% of patients. The incidence of the combined endpoint events was significantly lower in patients with early therapy than in those without (2.7 vs. 5.1%, P < 0.001). Inverse-probability-of-treatment weighting analysis demonstrated that early β-blocker therapy was associated with a low risk of combined endpoint events (HR = 0.641, 95% CI: 0.486–0.844, P = 0.002). Similar results were shown in multivariate Cox regression (HR = 0.665, 95% CI: 0.496–0.894, P = 0.007) and propensity score matching (HR = 0.633, 95% CI: 0.453–0.884, P = 0.007) analyses. A dose-response trend between the first-day β-blocker dosages and adverse outcomes was observed in a subset of participants with available data. No factor could modify the association of early treatment and the primary outcomes among the subgroups analyses. Conclusion Based on nationwide Chinese data, early oral β-blocker therapy is independently associated with a lower risk of poor in-hospital outcome in patients with STEMI and Killip class II or III heart failure.