Guidelines recommend immediate beta-blockers for acute myocardial infarction (AMI). Yet their benefit remains unclear for patients with preserved left ventricular ejection fraction (LVEF). A meta-analysis published in the Journal of Cardiology reviewed randomized controlled trials (RCTs) comparing standard therapy with or without beta-blockers in AMI patients with LVEF ≥40%. Researchers focused on efficacy and safety in this group.
The analysis included 19,826 participants from four RCTs. Half (9892) received beta-blockers; the rest (9934) did not. The primary outcome was a composite of all-cause death, myocardial infarction, and heart failure hospitalization. Safety endopoints were bradyarrhythmia events like bradycardia, AV block, or pacemaker need. The researchers used random-effect models for hazard ratios (HRs) with 95% CIs.
Key Findings
Beta-blockers showed no edge on the primary outcome (HR 0.93; 95% CI 0.82–1.04). Safety outcomes were similar too (HR 1.06; 95% CI 0.83–1.34). No differences emerged in individual components like death, MI, heart failure hospitalization, or stroke. Results held steady across subgroups.
Implications for Practice
In AMI patients with preserved LVEF, beta-blockers were not linked to better CV outcomes or more bradyarrhythmic risks versus non-beta-blocker therapy. These observational associations from RCTs highlight the need for further trials to define beta-blockers' role.