Bilateral unilateral internal mammary revascularization in patients with left ventricular dysfunction.

Aim: To investigate the survival benefit of bilateral internal mammary artery (BIMA) grafts in patients with left ventricular dysfunction.

Methods: Between 1996 and 2009, we performed elective, isolated, primary, multiple cardiac arterial bypass grafting in 430 consecutive patients with left ventricular ejection fraction ≤ 40%. The early and long-term results were compared between 167 patients undergoing BIMA grafting and 263 patients using left internal mammary artery (LIMA)-saphenous venous grafting (SVG).

Results: The mean age of the overall population was 60.1 ± 15 years. In-hospital mortality was not different between the two groups (7.8% 10.3%, = 0.49). Early postoperative morbidity included myocardial infarction (4.2% 3.8%, = 0.80), stroke (1.2% 3.8%, = 0.14), and mediastinitis (5.3% 2.3%, = 0.11). At 8-year follow-up, Kaplan-Meier-estimated survival (74.2% 58.9%, = 0.02) and Kaplan-Meier-estimated event-free survival (all cause deaths, myocardial infarction, stroke, target vessel revascularization, heart failure) (61.7% and 41.1%, < 0.01) were significantly higher in the BIMA group compared with the LIMA-SVG group in univariate analysis. The propensity score matching analysis confirmed that BIMA grafting is a safe revascularization procedure but there was no long term survival ( = 0.40) and event-free survival ( = 0.13) in comparison with LIMA-SVG use.

Conclusion: Our longitudinal analysis suggests that BIMA grafting can be performed with acceptable perioperative mortality in patients with left ventricular dysfunction.