Single Versus Multiple Inflow Source for Coronary Artery Bypass Surgery in Ischemic Cardiomyopathy

Abstract

Background and Objectives: The optimal grafting strategy for ischemic cardiomyopathy (ICMP) remains uncertain despite the growing heart failure population undergoing coronary artery bypass grafting (CABG). This study sought to explore the outcomes of CABG in ICMP patients according to the number of inflow sources. Methods: A total of 447 patients with an ejection fraction (EF) of <= 35% who underwent isolated CABG from 2009 to 2020 were analyzed. Patients were categorized into either a single inflow source group (single group, n=203), in which unilateral in situ internal thoracic artery (ITA) served as the sole inflow, or a multiple inflow source group (multiple group, n=244), utilizing additional inflow sources from the aorta or contralateral ITA. The primary outcome was all-cause mortality, analyzed after adjustment using the inverse-probability-of-treatment-weighting method. Results: There were no differences in the early outcomes between 2 groups. After adjustment, the single group exhibited significantly worse survival compared to the multiple group during a median follow-up of 5.3-years (adjusted hazard ratio, 1.88; 95% confidence interval, 1.26-2.80; p=0.001), particularly in the subgroup of patients without a recent myocardial infarction within 1 month (p=0.005) and those with an EF of >= 25% (p=0.007). At the last follow-up echocardiography (>6 months), the multiple group showed a significantly higher postoperative EF (p=0.009) and a smaller left ventricular end-systolic dimension (p=0.027) compared to the single group, which had not shown significant differences preoperatively. Conclusions: In ICMP patients, CABG using multiple inflow sources was associated with improved outcomes, particularly in those without recent or profound myocardial injury.