Beta-blockers show no mortality benefit in MI patients with preserved ejection fraction

A meta-analysis published in a major journal examined the effect of beta-blockers versus no beta-blockers in adults with myocardial infarction (MI) and left ventricular ejection fraction (LVEF) ≥ 40%. The analysis included 23,524 patients from multiple randomized controlled trials. The primary outcomes were all-cause mortality, recurrent MI, and heart failure (HF). Secondary outcomes included major adverse cardiovascular events (MACE), cardiovascular death, stroke, and revascularization.

For recurrent acute myocardial infarction (AMI), beta-blockers did not significantly reduce the risk compared to no beta-blockers (HR: 0.89; 95% CI [0.78, 1.02]; P = 0.1). For heart failure, the result was also not significant (HR: 0.92; 95% CI [0.71, 1.20]; P = 0.54). All-cause mortality showed no significant reduction (HR: 0.97; 95% CI [0.85, 1.10]; P = 0.63). These findings indicate that beta-blockers offer no prognostic advantage in this population.

Secondary outcomes were reported but specific effect sizes were not provided in the available data. Safety and tolerability details were not reported in the meta-analysis, including adverse events, serious adverse events, and discontinuations. This limits the ability to assess the risk-benefit balance fully.

These results contrast with the well-established benefit of beta-blockers in patients with reduced LVEF (< 40%), where multiple landmark trials have shown mortality reductions. The current analysis suggests that the benefit does not extend to those with preserved or mildly reduced ejection fraction.

Key limitations include low to moderate certainty of evidence, as rated by the authors. Trial sequential analysis (TSA) boundaries were not crossed, indicating that the cumulative evidence may not be sufficient to definitively rule out a small effect. Meta-regression identified no significant effect modifiers, meaning no subgroup (e.g., by age, sex, or comorbidities) showed a clear benefit.

For clinical practice, routine long-term use of beta-blockers in post-MI patients with LVEF ≥ 40% offers no prognostic advantage and should be reserved for specific indications such as reduced LVEF, angina, arrhythmia, or hypertension. Clinicians should not infer causation from association, and the findings do not support overstating the benefit of beta-blockers in this population.

Unanswered questions remain, including whether specific beta-blocker types or doses might have different effects, and whether longer follow-up could reveal late benefits. Further high-quality trials are needed to clarify the role of beta-blockers in this large patient group.