Impact of Beta-Blocker Prescription at Discharge on Long-term Clinical Outcomes in ST elevation Myocardial Infarction Patients with Reduced LVEF treated with Drug-eluting Stents

초록

Background The use of β-blockers in patients with myocardial infarction (MI) and reduced left ventricular ejection fraction (LVEF <40%) is well established. However, limited data are available regarding the impact of β-blocker therapy at discharge on the long-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) treated with drug-eluting stents (DESs). Methods We analyzed data from the Korea Acute Myocardial Infarction Registry (KAMIR) involving STEMI patients with reduced LV ejection fraction (<40%) treated with DESs. Patients were grouped into β-blocker users and non-users 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, MI, and revascularization. Inverse probability of treatment weighting (IPTW) was used to adjust for confounders. Results After IPTW, baseline characteristics were well balanced between the β-blocker and non-user groups. At 1 year after discharge, the incidence of total death (4.5% vs. 7.4%, HR: 0.583, 95% CI: 0.434–0.782, P<0.001) and MACE (9.3% vs. 12.8%, HR: 0.700, 95% CI: 0.563–0.870, P=0.001) was significantly lower in the β-blocker group compared to the non-user group. Over the 3-year follow-up, the β-blocker group continued to show a lower risk of total death (8.0% vs. 11.2%, HR: 0.684, 95% CI: 0.542–0.863, P=0.002) and MACE (15.2% vs. 18.6%, HR: 0.784, 95% CI: 0.654–0.940, P=0.009). Conclusions In STEMI patients with reduced LVEF treated with DESs, discharge prescription of β-blockers was associated with a significant reduction in the risk of total death and MACE at both 1 and 3 years compared to non-users. These findings highlight the potential long-term benefits of β-blocker therapy in this population.