Effects of Long-Term Carvedilol Therapy in Patients With ST-Segment Elevation Myocardial Infarction and Mildly Reduced Left Ventricular Ejection Fraction.

The benefits of long-term oral β-blocker therapy in patients with ST-segment elevation myocardial infarction (STEMI) with mildly reduced left ventricular ejection fraction (LVEF; ≥40%) are still unknown. We sought to evaluate the efficacy of β-blocker therapy in patients with STEMI with mildly reduced LVEF. In the CAPITAL-RCT (Carvedilol Post-Intervention Long-Term Administration in Large-Scale Randomized Controlled Trial), patients with STEMI with successful percutaneous coronary intervention with an LVEF of ≥40% were randomly assigned to carvedilol or no β-blocker therapy. Among 794 patients, 280 patients had an LVEF of <55% at baseline (mildly reduced LVEF stratum), whereas 514 patients had an LVEF of ≥55% at baseline (normal LVEF stratum). The primary end point was a composite of all-cause death, myocardial infarction, hospitalization for acute coronary syndrome, and hospitalization for heart failure, and the secondary end point was a cardiac composite outcome: a composite of cardiac death, myocardial infarction, and hospitalization for heart failure. The median follow-up period was 3.7 years. The lower risk of carvedilol therapy relative to no β-blocker therapy was not significant for the primary end point in either the mildly reduced or normal LVEF strata. However, it was significant for the cardiac composite end point in the mildly reduced LVEF stratum (0.82/100 person-years vs 2.59/100 person-years, hazard ratio 0.32 [0.10 to 0.99], p = 0.047) but not in the normal LVEF stratum (1.48/100 person-years vs 1.06/100 person-years, hazard ratio 1.39 [0.62 to 3.13], p = 0.43, p for interaction = 0.04). In conclusion, long-term carvedilol therapy in patients with STEMI with primary percutaneous coronary intervention might be beneficial for preventing cardiac-related events in those with a mildly reduced LVEF.