Are two internal thoracic grafts better than one? An analysis of 5301 cases.

Abstract

Although bilateral internal thoracic artery (BITA) grafting is associated with improved survival, many surgeons are reluctant to use this technique due to its greater complexity and the potentially increased risk of sternal infection. This observational study examined if BITA grafting provides improved outcomes compared with single internal thoracic artery (SITA) grafting in patients with multivessel coronary disease. Patients in our institution who underwent BITA grafting during 1996-2011 were compared to those who underwent SITA grafting during the same period. To adjust for differences in demographic and clinical characteristics, patients were matched by propensity score. The Cox model was used to identify predictors of decreased survival and the Kaplan-Meier analysis was performed, both for the entire cohort and for the matched cohort. SITA patients were older than BITA patients, included more females, and were more likely to have chronic obstructive lung disease, an ejection fraction <30%, diabetes, renal insufficiency, peripheral vascular disease and emergency and repeat operations. Three-vessel and left main diseases were more common among BITA patients, and operative mortality was reduced (2.1% vs 3.6% for SITA, P = 0.002). Sternal infection and stroke rates were similar for the groups. Ten-year Kaplan-Meier survival of BITA patients was better (71.2% vs 56.8%, respectively, P < 0.001). BITA grafting was found to be a predictor of better survival in the analysis of the matched cohort (P < 0.001). Our results support the routine use of BITA grafting in patients who undergo myocardial revascularization.