Free vs In-Situ Right Internal Mammary Artery as a Conduit in Coronary Artery Bypass Surgery: A Meta-Analysis

In this article, the authors performed a meta-analysis of 13 studies comprising 9,899 coronary artery bypass grafting (CABG) patients, comparing free right internal mammary artery (RIMA) (n = 3,095) vs in-situ RIMA (n = 6,804) as a second arterial conduit. With follow-up ranging from 1 to 20 years, random-effects analysis showed no significant differences in overall mortality (hazard ratio [HR] 1.16, 95 percent confidence interval [CI] 0.79 to 1.69), graft occlusion (HR 1.04, 95 percent CI 0.90 to 1.21), major adverse cardiac events (MACE) (HR 0.87, 95 percent CI 0.62 to 1.21), or repeat revascularization (HR 1.34, 95 percent CI 0.68 to 2.66). Despite moderate heterogeneity in secondary endpoints, findings were robust on sensitivity analyses. Clinically, free RIMA and in-situ RIMA appeared to have similar outcomes in this study.