Bilateral vs Single Internal Mammary Artery Grafts for Coronary Artery Bypass in the United States

BackgroundThe use of the bilateral internal mammary artery (BIMA) in coronary bypass grafting remains controversial. The objective this study was to investigate long-term outcomes using BIMA vs single (SIMA) United States.MethodsMedicare beneficiaries who underwent primary isolated surgery SIMA or from 1999 2010 were included retrospective study, with follow-up through 2014. Greedy matching algorithms used for 1:4 on propensity score based age, gender, year surgery, and comorbidities. Kaplan-Meier survival analyses performed. outcome death any cause.ResultsA total 1,156,339 25,005 patients 72 ± 7.6 years age 70.3 7.9 BIMA, respectively. Matching created comparable groups 95,780 24,160 patients. Matched median 11.8 12.4 (P < .001) 9.6 10 diabetic = .006), At follow-up, respective rates 58.3% 61.1%, stratified matched 1, 2, 3, 4 more aortocoronary bypasses 12.3 .005), 11.7 12.5 .001), 11.9 .01), 11.4 12 .02), respectively.ConclusionsPrimary rather than associated improved survival. This advantage independent grafts patient diabetes status. States. Medicare cause. A Primary