Late Outcomes of In Situ versus Composite Bilateral Internal Thoracic Artery Revascularization.

Abstract Background We compared two 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 1996-2011. 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). Early mortality (2.2% vs. 2.0%, p=0.787) and other early adverse outcomes did not differ significantly between the groups. Long-term (fifteen-year) survival was marginally significant in favor of the in situ group (53.5% vs 49.5%, p=0.05); this difference disappeared after 20 years. Configuration strategy was not found to be a predictor for better 15-year survival in multivariable analysis (HR: 0.97 95%CI 0.85-1.09, p=0.568). An additional analysis compared matched groups of 995 patients each, who underwent the two configuration strategies, and found no differences in early outcome or late survival between the groups. Conclusions This study demonstrated the safety and effectiveness of two strategies for bilateral internal thoracic artery revascularization to the left side, with comparable early outcomes and long-term survival.