Comparison of Early and Long-Term Mortality in Patients With Reduced and Preserved Ejection Fraction Undergoing Coronary Artery Bypass Graft: A Systematic Review and Meta-Analysis

The aim of this study was to compare early and long-term mortality in patients with reduced and preserved ejection fraction (EF) undergoing coronary artery bypass graft (CABG). This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Two investigators independently conducted a systematic and comprehensive search of PubMed, EMBASE, and Scopus from inception to July 15, 2023, using the search terms "reduced ejection fraction," "preserved ejection fraction," "coronary artery bypass surgery," and "mortality." Boolean operators (AND, OR) were used with medical subject heading (MeSH) terms to refine the search. The reference lists of all included articles were manually searched to identify potentially relevant studies. We restricted our search to studies published in the English language. The outcomes assessed in this meta-analysis included short-term mortality (including in-hospital and 30-day mortality) and long-term mortality. A total of five studies were included in this meta-analysis. The pooled sample size is 94,399 participants. Pooled analysis showed that the risk of early mortality was significantly higher in patients with reduced EF compared to patients with preserved EF (risk ratio, RR: 2.14, 95% CI: 1.50 to 3.06). The pooled analysis also reported that late mortality was significantly higher in patients with reduced EF compared to patients with preserved EF (RR: 1.67, 95% CI: 1.35 to 2.08). The pooled analysis of studies demonstrated a significantly higher rate of both early and late mortality in patients with reduced EF, emphasizing the importance of EF assessment in risk stratification for CABG patients.