CLINICAL EFFECTS OF BETA-BLOCKERS IN HYPERTENSIVE PATIENTS WITH ACUTE MYOCARDIAL INFARCTION AFTER ONE YEAR

Abstract

Objective: Although the oral beta-blocker therapy is recommended at least 3 years after acute myocardial infarction (AMI), especially in hypertensive patients to control blood pressure, the evidence to support its clinical benefit is very poor. This study aimed to investigate the long-term clinical effects of beta-blockers in hypertensive patients with AMI who had no major adverse cardiac events (MACE) until 1 year after the initial attack. Design and method: Among 13,624 patients who were enrolled in nationwide AMI database of South Korea, the KAMIR-NIH Registry, 4,610 hypertensive patients, who underwent echocardiographic study and had no MACE (a composite of cardiac death, MI, revascularization or readmission due to heart failure) until 1 year, were selected in this study. Results: Beta-blockers were prescribed in 4,237 hypertensive patients (92%) at 1 year after AMI. On multivariable Cox-proportional hazard analysis, beta-blockers further reduced 1-year cardiac death (1.4 vs. 7.5/100 person-year; HR 0.23; 95% CI 0.14–0.38; p < 0.001), MI (1.1 vs. 3.1/100 person-year; HR 0.33; 95% CI 0.16–0.68; p = 0.002), and MACE (5.8 vs. 11.1/100 person-year; HR 0.54; 95% CI 0.37–0.79; p = 0.001). However, clinical outcomes showed a significant interaction with left ventricular ejection fraction (LVEF). Beta-blockers decreased 1-year MACE of patients with LVEF =<40% (11.3 vs. 24.5/100 person-year; HR 0.40; 95% CI 0.19–0.84; p = 0.015) and 40% <LVEF <50% (6.3 vs. 18.9/100 person-year; HR 0.43; 95% CI 0.22–0.85; p = 0.015, but not those with LVEF >=50% (4.7 vs. 5.8/100 person-year; HR 0.77; 95% CI 0.42–1.43; p = 0.411). ∗HR; hazard ratio, CI; confidence interval. Conclusions: Beta-blockers improved the clinical outcomes in hypertensive patients with mid-range as well as reduced LVEF until 2 years after AMI. However, its benefit in hypertensive patients with preserved LVEF was questionable.