Efficacy of Long-Term Oral Beta-Blocker Therapy in Patients Who Underwent Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction With Preserved Left Ventricular Ejection Fraction: A Systematic Review and Meta-analysis

ABSTRACTFollowing the results of the first multi-center, prospective randomized clinical trial (RCT) evaluating long-term efficacy of oral beta-blockers in patients with preserved left ventricular ejection fraction (LVEF) after ST elevation myocardial infarction (STEMI), we decided to conduct an updated systematic review and meta-analysis to evaluate the long-term efficacy of oral beta-blockers use in patients with preserved LVEF who underwent percutaneous coronary intervention (PCI) for STEMI. A time limited search from 01/01/1999 to 4/16/2020 on PubMed and EMBASE was conducted on April 16, 2020 for observational studies and clinical trials evaluating the efficacy of long-term oral beta-blockers in patients with preserved LVEF after STEMI treated with PCI. The comparative outcomes between beta-blockers and non-beta-blockers were assessed by pooling weighted odds ratio (OR) with 95% confidence interval (CI) using random effects model. The outcomes of interest were all-cause mortality and major adverse cardiac events (MACE). Twelve studies (11 observational and one RCT) comprising 32,108 patients (19,740 on beta-blocker therapy and 12,368 without beta-blocker therapy) were included. Of which, 75% percent were male (mean age 64 years63.87 ± 3.01 years on beta-blocker therapy and 64.76 ± 3.02 years on non-beta-blocker therapy; p= 0.129) with a follow up of up to 4.7 years. Unadjusted all-cause mortality [OR= 0.58 (95% CI0.42-0.79)] and adjusted all-cause mortality [OR= 0.64 (95% CI0.48-0.87)] were significantly lower in patients on long-term beta-blocker therapy group. However, unadjusted MACE [OR= 0.87 (95% CI0.70-1.08)] was not reduced with beta-blocker therapy in these patients. Patients with preserved LVEF following STEMI treated with PCI on long-term oral beta-blocker therapy have a significant reduction in risk of all-cause mortality, without an effect on MACE rates. The only RCT trial included showed neutral effect so results of ongoing randomized clinical trials are anticipated. Considering that the only high-quality data (RCT) suggest a neutral effect, one should be cautious in interpreting the conclusion.