Left internal mammary artery use in patients with poor left ventricular ejection fraction: a propensity-matched analysis of mid-term survival.

We aimed to determine whether the use of left internal mammary artery (LIMA) to the left anterior descending (LAD) artery during coronary artery bypass grafting (CABG) confers an improved survival benefit to patients with an impaired preoperative left ventricular ejection fraction (LVEF). Between April 1997 and March 2004, 7198 consecutive patients underwent first time CABG to the LAD. There were 627 patients who had an LVEF <30% and of these, 548 patients (87.4%) received a LIMA graft, while 79 patients (12.6%) did not. A propensity-matched analysis was performed to provide matched cohorts for analysis of deaths occurring over time, which were described using Kaplan-Meier techniques. Propensity-matching produced two cohorts of 77 patients with or without the use of LIMA. Patient characteristics were reasonably matched between the groups. Forty-six (29.9%) deaths occurred in the propensity-matched groups. Freedom from death in patients with LIMA used at 4-years was 77.1%, compared with 60.7% for the patients with no LIMA used (P=0.026). The use of the LIMA as a bypass conduit is not contraindicated in patients with a poor preoperative LVEF. The usage of LIMA markedly improves survival.