Does the use of bilateral internal mammary artery grafts impact survival of veterans undergoing coronary artery bypass surgery?

Background The impact of bilateral internal mammary artery (BIMA) versus single left internal mammary artery (LIMA) grafts on long-term survival in veterans after coronary artery bypass graft (CABG) surgery is unknown. Methods A review of prospectively collected data identified all patients (n = 784) who underwent primary isolated CABG surgery from December 1991 through December 1998. Grafting was performed with LIMA in 713 (90.9%) patients and with BIMA in 71 (9.1%) patients. We identified 66 propensity-matched patient pairs. Results The matched cohort was all male. The mean follow-up was 9.7 ± 3.8 years. Comparing matched patients showed no significant survival benefit for the BIMA group versus the LIMA group at 5 years (89% versus 86%) and 10 years (73% versus 69%) (P = .99). Factors associated with decreased survival were advanced age, higher New York Heart Association heart failure class, and diabetes. Conclusions Using BIMA grafting instead of LIMA grafting had no significant survival benefit for male veterans who underwent CABG surgery. Further study is needed to fully evaluate the role of BIMA grafting in this unique patient population.