Impact of 2nd-generation versus 3rd-generation beta-blockers on long-term clinical outcomes in STEMI patients treated with drug-eluting stents

Abstract Background The comparative effectiveness of 2nd-generation (2G; Bisoprolol) and 3rd-generation (3G: Nebivolol, Carvedilol) β-blockers in patients with ST-segment elevation myocardial infarction (STEMI) treated with drug-eluting stents (DESs) remains unclear. Methods We analyzed data from the Korea Acute Myocardial Infarction Registry (KAMIR) involving STEMI patients treated with DESs. Patients were classified into two groups based on the use of 2G or 3G β-blockers 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 confounders. Results After IPTW, baseline characteristics were balanced between the 2G and 3G β-blocker groups. At 1 year after discharge, the incidence of total death was similar between the two groups (1.9% vs. 1.7%, P=0.327), but the 3G group had a significantly lower incidence of MACE (6.0% vs. 5.1%, P=0.008). Over the 3-year follow-up, total death remained comparable between the two groups (4.1% vs. 3.7%, P=0.154, HR: 0.899, 95% CI: 0.777–1.040), while the 3G group had a significantly lower risk of MACE (11.3% vs. 10.2%, P=0.008, HR: 0.883, 95% CI: 0.807–0.967). Conclusions In STEMI patients treated with DESs, 3G β-blockers were associated with a significantly lower incidence of MACE at 1 and 3 years compared to 2G β-blockers, while the incidence of total death was similar between the two groups. These findings suggest that 3G β-blockers may offer additional long-term benefits in this population.