Abstract
The role of prophylactic beta-blocker therapy in patients treated with primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) who have mildly reduced or preserved left ventricular ejection fraction (LVEF) remains a subject of debate. This systematic review and meta-analysis aimed to evaluate the efficacy of beta-blocker therapy versus no beta-blocker therapy in this specific patient population. We searched PubMed, National Institutes of Health (NIH), Elsevier, Google Scholar, and ClinicalTrials.gov for studies published between 2014 and 2024. Eligible studies included randomized controlled trials (RCTs) and observational studies comparing beta-blockers with no beta-blockers in patients undergoing PCI for STEMI with an LVEF ≥ 40%. The primary outcome was all-cause mortality; secondary outcomes included cardiovascular mortality, reinfarction, and hospitalization for heart failure or stroke. Effect sizes were calculated as relative risk (RR) with 95% confidence intervals (CI). Our search yielded 187 articles, from which six studies (four observational and two RCTs) met the inclusion criteria, encompassing a pooled cohort of 28,736 patients (mean age: 63.5 years; 83% male). Of these, 13,650 (47.5%) received beta-blockers at hospital discharge. The meta-analysis of five studies (18,459 patients) indicated that beta-blocker use was associated with a significant reduction in all-cause mortality. However, heterogeneity was high; sensitivity analysis removing one influential RCT reduced I² to 55% and strengthened the significance. Subgroup analysis for cardiovascular mortality (four studies, 14,784 patients) showed a significant risk reduction in two observational studies but no significant effect in two RCTs. No significant differences were observed for reinfarction or hospitalization for heart failure or stroke. The quality of evidence from RCTs was deemed low due to their open-label design. In conclusion, while beta-blocker therapy may reduce all-cause mortality in post-PCI STEMI patients with preserved LVEF, its effect on cardiovascular mortality is inconsistent between study types. High-quality, blinded RCTs are warranted to definitively establish efficacy in this population.