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.

After the results of the first multicenter, 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-blocker use in patients with preserved LVEF who underwent percutaneous coronary intervention (PCI) for STEMI. A time-limited search from January 1, 1999, to April 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 event (MACE). Twelve studies (11 observational and 1 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 of 64 years: 63.87 ± 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% CI: 0.42-0.79)] and adjusted all-cause mortality [OR = 0.64 (95% CI: 0.48-0.87)] were significantly lower in patients on the long-term beta-blocker therapy group. However, unadjusted MACE [OR = 0.87 (95% CI: 0.70-1.08)] was not reduced with beta-blocker therapy in these patients. Patients with preserved LVEF after 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 included showed neutral effect, so results of ongoing RCTs are anticipated. Considering that the only high-quality data (RCT) suggest a neutral effect, one should be cautious in interpreting the conclusion.