Efficacy of Beta-blocker Therapy in Post-myocardial Infarction Patients with Preserved or Mildly Reduced Ejection Fraction: A Systematic Review and Meta-analysis
TL;DR
In contemporary reperfusion-era populations with pEF or mrEF, long-term beta-blocker therapy after MI does not confer significant reductions in mortality or recurrent MI, challenging the historical paradigm of universal post-MI beta-blockade and support a more selective, individualized approach guided by LVEF.
Abstract
Beta-blockers improve outcomes after myocardial infarction (MI) in patients with reduced left ventricular ejection fraction (LVEF), but their benefit in patients with preserved ejection fraction (pEF) or mildly reduced ejection fraction (mrEF) remains unclear in the era of modern reperfusion and optimized therapy. This study evaluates the long-term impact of beta-blockers in this population. Following a systematic search of four databases, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) in post–myocardial infarction patients with LVEF ≥40%, comparing long-term beta-blocker therapy with usual care. Primary outcomes were all-cause mortality and recurrent MI; secondary outcomes included cardiovascular (CV) mortality, heart failure hospitalization (HFH), malignant ventricular arrhythmias, ischemic stroke, and unplanned coronary revascularization. Data were pooled using random-effects models. Four multicenter RCTs (9892 patients in the beta-blocker group and 9934 in the control group) conducted between 2017 and 2024 were included, with a median follow-up of 3.5–3.7 years. Beta-blocker therapy was not associated with a significant reduction in all-cause mortality (hazard ratio [HR]: 0.98, confidence intervals [CI] 0.85–1.12) or recurrent MI (HR: 0.88, CI 0.74–1.05). No benefit was observed for secondary outcomes, including CV mortality, HFH, malignant arrhythmias, ischemic stroke, or unplanned revascularization. Heterogeneity was low to moderate, and study quality was moderate overall, with high certainty for primary outcomes. In contemporary reperfusion-era populations with pEF or mrEF, long-term beta-blocker therapy after MI does not confer significant reductions in mortality or recurrent MI. These findings challenge the historical paradigm of universal post-MI beta-blockade and support a more selective, individualized approach guided by LVEF.