Liberal bilateral internal thoracic artery use in people with diabetes neutralizes the negative impact of insulin-requiring status

Aims Bilateral internal thoracic artery (BITA) grafts are underused in insulin-dependent diabetic patients because of increased risk of postoperative complications. The impact of the insulin-requiring status on outcomes after routine BITA grafting was investigated in this retrospective study. Methods Skeletonized BITA grafts were used in 3228 (71.6%) of 4508 consecutive patients having multivessel coronary disease who underwent isolated coronary bypass surgery at the authors’ institution from January 1999 to August 2015. Among these BITA patients, diabetes mellitus and the insulin-requiring status were present in 972 (30.1%) and 237 (7.3%) cases, respectively. After the one-to-one propensity score-matching, 215 pairs of insulin-dependent/noninsulin-dependent people with diabetes were compared as the postoperative outcomes. The operative risk was calculated for each patient according to the logistic European System for Cardiac Operative Risk Evaluation (logistic EuroSCORE). Results As expected, insulin-dependent people with diabetes had higher risk profiles than noninsulin-dependent people with diabetes (median logistic EuroSCORE, 4.1 vs. 3.5%, P = 0.086). However, there were no differences in in-hospital mortality both in unmatched and propensity score-matched series (2.5 vs. 2%, P = 0.65 and 2.8 vs. 1.9%, P = 0.52, respectively). In propensity score-matched pairs, only prolonged invasive ventilation (P = 0.0039) and deep sternal wound infection (P = 0.071) were more frequent in insulin-dependent people with diabetes. No differences were found as the late outcomes. Conclusion In diabetic patients, the insulin-requiring status is by itself a risk factor neither for in-hospital death nor for poor late outcomes after routine BITA grafting. Only the risk of prolonged invasive ventilation and deep sternal wound infection are increased early after surgery.