Abstract 1564: Does Location of the Second Internal Thoracic Artery Graft Influence Outcome?

Objectives: To determine whether location of the second internal thoracic artery (ITA) graft used for bilateral ITA grafting affects mortality and morbidity of patients with 3-system coronary artery disease, and to identify factors associated with location of the second ITA. Methods: From 1/1972 to 6/2006, 3,611 patients with 3-system coronary artery disease underwent bilateral ITA grafting with one ITA to the left anterior descending (LAD) system and the second to either the circumflex (LCx; n=2,926) or right coronary artery (RCA; n=685) system. Follow-up was 9.2±7.2 years. Propensity score methodology was used to obtain risk-adjusted outcome comparisons between patients with the second ITA to the LCx vs RCA. Results: In-hospital mortality (0.34% vs 0.58%; P =.4), stroke (0.96% vs 0.88%; P =.8), myocardial infarction (1.3% vs 0.73%; P =.2), renal failure (0.44% vs 0.29%; P =.6), respiratory insufficiency (3.5% vs 3.8%; P =.7), and reoperation for bleeding (3.4% vs 3.2%; P =.8) were similar in patients who received the second ITA to the LCx or RCA, and remained similar after propensity score adjustment. Late survival was also similar (Fig .). Despite this, there has been a gradual decline in ITA to RCA grafting, particularly in the presence of severe LCx disease, but more use in women and in patients without RCA occlusion or distal stenoses. Conclusions: Contrary to prevailing wisdom that the second ITA graft should be anastomosed to the next most important left-sided coronary artery in 3-system disease, the second ITA graft may be placed to either the LCx or RCA system with similar early and late outcomes.