Exploring the Impact of Beta-Blockers Post-Acute Myocardial Infarction in Patients with Preserved Ejection Fraction: A Meta-Analysis

Background/Objectives: Previous research has established that beta-blockers significantly reduce all-cause mortality, cardiovascular mortality, and recurrent acute myocardial infarction (AMI) in patients with left ventricular dysfunction following AMI. However, their efficacy in patients with preserved left ventricular ejection fraction (LVEF) who undergo timely reperfusion and revascularization while receiving evidence-based medical management remains inconclusive. To address this uncertainty, we conducted a systematic review and meta-analysis to synthesize the available evidence on the impact of beta-blocker therapy in patients with AMI and preserved LVEF. Methods: A comprehensive literature search was conducted across PubMed, the Web of Science, and Scopus from their inception until November 2024. The search strategy incorporated three primary keywords and their corresponding Medical Subject Headings (MeSH) terms: “preserved”, “myocardial infarction”, and “beta-blocker”. Data analysis was performed using Review Manager 5.4 software. A random-effects model was applied to account for the study’s heterogeneity, while a fixed-effects model was utilized for homogeneous outcomes. Pooled odds ratios (ORs) and hazard ratios (HRs) were calculated for dichotomous outcomes, with a 95% confidence interval (CI) and a significance threshold of p < 0.05. Results: Beta-blocker therapy was significantly associated with a reduction in all-cause mortality compared to non-use, with an OR of 0.73 (95% CI: 0.61–0.88, p = 0.001) and an HR of 0.78 (95% CI: 0.67–0.91, p = 0.002). Similarly, beta-blocker administration was linked to a lower risk of cardiovascular mortality, demonstrating an OR of 0.76 (95% CI: 0.68–0.84, p < 0.00001) and an HR of 0.76 (95% CI: 0.59–0.99, p = 0.04). Furthermore, beta-blocker use was significantly correlated with a decreased risk of major adverse cardiovascular events (MACEs) compared to non-use, with an OR of 0.84 (95% CI: 0.75–0.95, p = 0.004) and an HR of 0.84 (95% CI: 0.71–0.99, p = 0.04). Conclusions: The current meta-analysis suggests a potential beneficial association between beta-blocker use and outcomes in patients with AMI and preserved LVEF, including lower rates of all-cause mortality, cardiovascular mortality, and MACEs; however, these findings should be interpreted with caution due to the observational nature of most included studies. Therefore, further randomized controlled trials (RCTs) are needed to confirm these findings, particularly in distinguishing outcomes among patients with and without heart failure.