Late Outcomes of In Situ Versus Composite Bilateral Internal Thoracic Artery Revascularization

Background: We compared 2 configurations for revascularization of the internal thoracic arteries to the anterior and lateral walls. In the “in situ” configuration, an in situ right internal thoracic artery supplies the left anterior descending territory, and an in situ left internal thoracic artery is grafted to the left circumflex territory. In the “composite” configuration, an in situ left internal thoracic artery is grafted to the left anterior descending artery and a free right internal thoracic artery is attached end-to-side to the left internal thoracic artery and supplies the lateral wall. Methods: We compared outcomes of all the patients treated in our center by the described strategies during 1996 through 2011. Results: Of 2951 patients, 1220 underwent composite grafting and 1731 underwent in situ grafting; the median follow-up was 15.1 years (interquartile range, 11.2-18.6 years). Early mortality (2.2% vs 2.0%, P =.787) and other early adverse outcomes did not differ significantly between the groups. Long-term (15-year) survival was marginally significant in favor of the in situ group (53.5% vs 49.5%, P =.05); this difference disappeared after 20 years. Configuration strategy was not a predictor for better 15-year survival in multivariable analysis (hazard ratio, 0.97; 95% confidence interval, 0.85-1.09; P =.568). An additional analysis compared matched groups of 995 patients each who underwent the 2 configuration strategies and found no differences in early outcome or late survival between the groups. Conclusions: This study demonstrated the safety and effectiveness of 2 strategies for bilateral internal thoracic artery revascularization to the left side, with comparable early outcomes and long-term survival.