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Introduction Beta-blockers are routinely prescribed following myocardial infarction (MI) due to established mortality benefit in patients with reduced left ventricular ejection fraction (LVEF). However, their long-term benefit in patients with preserved LVEF (≥50%) in the contemporary era of revascularization and optimal secondary prevention remains uncertain. We conducted a systematic review and Bayesian meta-analysis and contextualized the findings with recently published randomized evidence.Methods PubMed, Embase, and Scopus were searched up until December 2020 for randomized and observational studies comparing beta-blocker therapy with no beta-blocker therapy in adults with prior MI and preserved LVEF (≥50%). The primary outcome was all-cause mortality. Bayesian random-effects models were used to estimate risk ratios (RRs) with 95% credible intervals (CrIs). Time-to-event analyses were performed using reconstructed individual patient data from published Kaplan–Meier curves.Results Six studies, including 17,068 patients, met inclusion criteria. Beta-blocker therapy was not associated with a significant reduction in all-cause mortality (RR 0.79; 95% CrI 0.55–1.06) or secondary outcomes, including cardiovascular death, recurrent MI, heart failure hospitalization, stroke, major adverse cardiovascular events, or unplanned revascularization. Between-study heterogeneity was low to moderate. A frequentist stratified Cox model suggested a modest survival benefit (HR 0.87; 95% CI 0.81–0.92); however, Bayesian survival modelling showed substantial uncertainty (HR 0.60; 95% CrI 0.26–1.41). Contemporary randomized trial data in preserved LVEF populations consistently demonstrated neutral effects.Conclusions In patients with preserved LVEF following MI, beta-blocker therapy was not associated with a clear reduction in mortality or major cardiovascular events. Clinically, these findings suggest that routine long-term beta-blocker therapy should not be continued in this population unless there is another clear indication (e.g. arrhythmia, hypertension, or angina). Future research should prioritize defining optimal treatment duration and identifying subgroups who may benefit.