Survival outcomes and predictors following coronary artery bypass grafting in patients with preoperative left ventricular dysfunction

BACKGROUND: Left ventricular dysfunction (EF < 50%) is an independent risk factor for undergoing coronary artery bypass grafting (CABG), which has been shown to improve ejection fraction (EF) in patients with ischemic cardiomyopathy. However, whether the short-term improvement in EF can improve survival outcomes remains uncertain. METHODS: In this retrospective cohort study, we included patients with left ventricular ejection fraction (LVEF) < 50% undergoing CABG from 2013 to 2023. Clinical characteristics were extracted from the data registry. Univariate and multivariate logistic regression analyses identified independent predictors, while Kaplan-Meier analysis with log-rank test compared survival outcomes among LVEF-stratified subgroups. RESULTS: From 2013 to 2023, 362 patients (85.6% male; mean age 58.5) were enrolled. The 5-year Kaplan-Meier estimates for event-free and overall survival were 80.1% and 92.5%, respectively. Landmark analysis showed 72 (19.9%) patients experienced major adverse cardiovascular events, with significant differences between LVEF subgroups (improvement vs. non-improvement; p < 0.001). Multivariable logistic regression identified independent predictors of LVEF improvement: smoking status (p < 0.001), preoperative LVEF < 35% (p < 0.001), dyslipidemia (p = 0.012), and diseased coronary arteries (p < 0.001). Patients with postoperative EF improvement had significantly better overall survival (p < 0.001) and event-free survival (p < 0.001) than those without. CONCLUSION: The 5-year Kaplan-Meier estimates showed EF improvement early after CABG in patients with preoperative cardiac dysfunction predicted better survival. This highlights the need for closer postoperative monitoring and proactive management in this population. Additionally, interventions with proactive patient education should address factors causing postoperative LVEF non-improvement.