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

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

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).

The mean age of the overall population was 60.1 ± 15 years. In-hospital mortality was not different between the two groups (7.8% vs 10.3%, P = 0.49). Early postoperative morbidity included myocardial infarction (4.2% vs 3.8%, P = 0.80), stroke (1.2% vs 3.8%, P = 0.14), and mediastinitis (5.3% vs 2.3%, P = 0.11). At 8-year follow-up, Kaplan-Meier-estimated survival (74.2% vs 58.9%, P = 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%, P < 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 (P = 0.40) and event-free survival (P = 0.13) in comparison with LIMA-SVG use.

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