Abstract 4373262: Impact of β-Blocker Nebivolol versus Bisoprolol Prescription at Discharge on Long-term Clinical Outcomes in ST elevation Myocardial Infarction Patients with Reduced Left Ventricular Ejection Fraction (<40%) treated with Drug-elut

Background: The comparative long-term outcomes of Nebivolol and Bisoprolol in ST-segment elevation myocardial infarction (STEMI) patients with reduced left ventricular ejection fraction (LVEF <40%) treated with drug-eluting stents (DESs) are not well understood. This study evaluated the efficacy and safety of these β-blockers in this population. Methods: We analyzed data from the Korea Acute Myocardial Infarction Registry (KAMIR) involving STEMI patients with reduced LVEF treated with DESs. Patients were grouped based on Nebivolol or Bisoprolol prescription at discharge and followed for up to 3 years. The primary endpoint was all-cause death, while the secondary endpoint was major adverse cardiac events (MACE), defined as a composite of all-cause death, myocardial infarction (MI), and revascularization. Inverse probability of treatment weighting (IPTW) was used to adjust for baseline confounders. Results: After IPTW adjustment, baseline characteristics were well balanced between the Nebivolol group (n=654) and the Bisoprolol group (n=663). At 1 year, the incidence of total death was similar between the two groups (3.2% vs. 4.4%, HR: 0.724, 95% CI: 0.408–1.283, P=0.313), whereas the incidence of MACE was significantly lower in the Nebivolol group (5.2% vs. 10.0%, HR: 0.495, 95% CI: 0.322–0.760, P=0.001). Over the 3-year follow-up, the incidence of total death (5.5% vs. 7.1%, HR: 0.762, 95% CI: 0.486–1.193, P=0.257) remained comparable, but the incidence of MACE continued to be significantly lower in the Nebivolol group (9.9% vs. 15.8%, HR: 0.586, 95% CI: 0.421–0.815, P=0.002). Conclusions: In STEMI patients with reduced LVEF treated with DESs, discharge prescription of Nebivolol was associated with a significantly lower incidence of MACE compared to Bisoprolol, while total death remained similar between the two groups after IPTW adjustment. These findings suggest that Nebivolol may offer additional benefits in reducing MACE in this population.