Impact of 2nd-Generation versus 3rd-Generation (3-Blocker Prescription at Discharge on Long-term Clinical Outcomes in ST elevation Myocardial Infarction Patients with Reduced Left Ventricular Ejection Fraction (<40%) treated with Drug-eluting Stents

초록

Background: The comparative effectiveness of 2nd-generation β-blockers (2G-BB, Bisoprolol) and 3rd-generation β-blockers (3G-BB, Carvedilol and Nebivolol) in ST-segment elevation myocardial infarction (STEMI) patients with reduced left ventricular (LV) ejection fraction (<40%) treated with successful drug-eluting stent (DES) implantation is not well established. This study aimed to evaluate long-term outcomes of these two β-blocker generations. 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 discharge prescription of 2nd-generation or 3rd-generation β-blockers 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 confounders. Results: After IPTW adjustment, baseline characteristics were well balanced between the 3G BB group (n=1,317) and the 2G BB group (n=1,384). At 1 year, there was no significant difference in the incidence of total death (3.6% vs. 4.6%, HR: 0.775, 95% CI: 0.527–1.141, P=0.207) and MACE (8.3% vs. 9.8%, HR: 0.842, 95% CI: 0.647–1.096, P=0.204) between the two groups. Over the 3-year follow-up, the incidence of total death (6.5% vs. 7.1%, HR: 0.916, 95% CI: 0.678–1.236, P=0.593) and MACE (13.8% vs. 15.2%, HR: 0.895, 95% CI: 0.722–1.110, P=0.326) remained comparable between the two groups. Conclusion: In STEMI patients with reduced LVEF treated with DESs, discharge prescriptions of 2nd- and 3rd-generation β-blockers resulted in similar long-term outcomes for all-cause death and MACE after IPTW adjustment.