β-Blocker Therapy in the Era of Primary Percutaneous Intervention for ST Elevation Myocardial Infarction

OBJECTIVES: With the present therapeutic advances in the era of primary percutaneous coronary intervention (PCI), the role of β-blockers in ST elevation acute myocardial infarction (STEMI) has remained contentious. METHODS: We analyzed the data and clinical outcomes of 901 STEMI patients who had undergone primary PCI. We classified the patients into β-blocker (n = 598) and non-β-blocker groups (n = 303). RESULTS: The cumulative incidence of all-cause death was 10.0% in the β-blocker group and 25.4% in the non-β-blocker group (p < 0.001). The incidence of major adverse cardiac events (MACE) was 22.1% in the β-blocker group and 34.3% in the non-β-blocker group (p < 0.001). The relative hazard ratio (HR) of β-blockers for all-cause death and MACE with low left ventricle ejection fraction (LVEF; <50%) was 0.55 [95% confidence interval (CI) 0.35-0.86, p = 0.009] and 0.75 (95% CI 0.51-1.09, p = 0.125), respectively. In patients with normal LVEF (≥50%), the relative HR of β-blockers for death and MACE were 0.50 (95% CI 0.29-0.88, p = 0.016) and 0.75 (95% CI 0.51-1.12, p = 0.162), respectively. After propensity score matching of the difference of the baseline characteristics, the Kaplan-Meier survival curve demonstrated lower mortality in the β-blocker group than in the non-β-blocker group with both low LVEF and normal LVEF (p = 0.02 and p = 0.001, respectively). CONCLUSIONS: β-Blockers have beneficial clinical outcomes in the era of primary PCI for STEMI, regardless of the LVEF.