Bilateral versus single internal thoracic artery grafting in oral-treated diabetic subsets: comparative seven-year outcome analysis

Background Recent interest has focused on the use of arterial conduits in diabetic subsets. To date, the long-term benefits of bilateral internal thoracic artery (BITA) grafting in this subgroup remain in question. Methods Two hundred eighty-five consecutive oral-treated diabetics operated on nonemergent basis (1996 to 1998) were compared according to the surgical technique, left-sided skeletonized BITA (n = 228) or single internal thoracic artery- saphenous veins (SITA) (n = 57). Patients with chronic lung disease, usually preselected to SITA grafting, were not included. Results The respective grafts to patient ratio was 3.1 ± 1 and 3.2 ± 0.8 for the SITA and BITA groups (p = NS). Complementary conduits used in the BITA group were gastroepiploic arteries (25%) and saphenous veins (13%). Early outcome was comparable, including the incidence of deep sternal infections (1.8% in both groups). During follow-up (range, 4 to 7.5 years; median, 5), there were less repeat revascularizations (4.4% vs 12.3%, p = 0.025) and major adverse cardiac events (MACE) (11.2% vs 36.8%, p< 0.0001) in the BITA group. At 7 years, survival (Kaplan-Meier) (75% vs 59%, p = 0.006, log-rank), freedom from cardiac mortality (92% vs 68%, p< 0.0001), and freedom from MACE (70% vs 59%, p = 0.004) were superior in the BITA group. Multivariate analysis identified the use of BITA as a protective factor against the occurrence of late cardiac mortality (odds ratio [OR] 0.2) and MACE (OR 0.3); conversely, SITA-saphenous vein arrangements increased the risk by fivefold (OR 5, confidence interval limits [CL] 1.6 to 16.6, p = 0.005) and threefold (OR 3.3, CL 1.5 to 9, p = 0.005), respectively. Conclusions Left-sided BITA grafting confers improved long-term survival and event-free survival in oral-treated diabetics. We, therefore, recommended this approach in this diabetic subset.