Sequential Internal Thoracic Artery Bypass Is Safe but Does Not Improve Survival

Abstract

The benefit of adding an internal thoracic artery (ITA) sequential bypass to single or bilateral ITA graft to improve arterial revascularization is not established. The goal of this study is to evaluate the safety and the potential benefit of ITA sequential bypass in coronary artery surgery. We retrospectively reviewed a cohort of 1,400 consecutive, prospectively followed patients who underwent off-pump coronary artery bypass surgery for multivessel disease between September 1996 and November 2007 at the Montreal Heart Institute. Among them, 1,315 (93.9%) patients had 2- or 3-vessel disease and received at least 1 ITA graft. The following 4 groups were investigated: group 1, single ITA grafting alone (n=758); group 2, single ITA+sequential grafting (n=151); group 3, bilateral ITA grafting alone (n=308); and group 4, bilateral ITA+sequential grafting (n=98). Mean follow-up was 63±33 months and completed in 97% of the cohort. Single ITA patients were older, had more diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, emergency surgery, and heart failure. The rates of complete revascularization, conversion to cardiopulmonary bypass, perioperative mortality, and myocardial infarction were similar in all groups. After correcting for risk factors, better overall, cardiac, and major adverse cardiac event (MACE)-free survival were observed in the bilateral ITA groups compared with the single ITA groups. Adding sequential ITA bypass grafting did not significantly impact survival or MACE-free survival. In our series, bilateral ITA grafting improved overall and MACE-free survival. Adding a sequential ITA bypass grafting was safe but did not add significant benefit in off-pump coronary artery bypass surgery.