Clinical outcomes of beta-blocker therapy after myocardial infarction in patients with preserved or mildly reduced ejection fraction
B L Resende, A M Pinto, E Mata, J Portugues, S Ribeiro, J Gameiro, A Lourenco, L GoncalvesAbstract
Background
While beta-blockers are well established for secondary prevention after myocardial infarction (MI) in patients with reduced left ventricular ejection fraction (LVEF), their long-term benefit in the reperfusion era among those with preserved (pEF) or mildly reduced (mrEF) LVEF remains uncertain in the era of modern reperfusion and optimized medical therapy. This study aimed to evaluate the efficacy and prognostic relevance of beta-blockers in contemporary post-MI patients without left ventricular systolic dysfunction.
Methods
Following PRISMA guidelines, we conducted a systematic search of CENTRAL, PubMed, Scopus, and EMBASE identified randomized controlled trials (RCTs) comparing long-term beta-blocker therapy versus usual care in post-MI patients with LVEF ≥ 40%. Primary outcomes were all-cause mortality and recurrent MI; secondary outcomes included cardiovascular (CV) mortality, heart failure hospitalization (HFH), malignant ventricular arrhythmias, stroke, and unplanned revascularization. Random-effects meta-analyses were performed using inverse-variance weighting.
Results
Four multicenter RCTs (2017–2024) comprising 19,826 patients (mean follow-up 3.6 years) met inclusion criteria. Beta-blocker therapy did not significantly reduce all-cause mortality (HR 0.98, 95% CI 0.85–1.12; I² = 0%) or recurrent MI (HR 0.88, 95% CI 0.74–1.05; I² = 32%). No significant differences were observed for CV mortality (HR 1.15, 95% CI 0.88–1.52), HFH (HR 0.85, 95% CI 0.61–1.19), stroke (RR 1.13, 95% CI 0.77–1.65), or revascularization (HR 1.00, 95% CI 0.85–1.18). Sensitivity analyses confirmed robustness, and heterogeneity was low. The certainty of evidence was rated high for primary outcomes.
Conclusions
In the contemporary reperfusion era, long-term beta-blocker therapy after MI does not confer significant reductions in mortality or recurrent ischemic events among patients with preserved or mildly reduced LVEF. These findings support individualized, risk-based continuation strategies, reserving chronic beta-blockade for patients with residual ventricular dysfunction or other specific indications.For image description, please refer to the figure legend and surrounding text.