Effect of Diabetes Mellitus on Complication Rates of Coronary Artery Bypass Grafting

Abstract

Previous studies have shown that diabetes mellitus (DM) is a risk factor for postoperative coronary artery bypass grafting (CABG) complications. More contemporary studies are needed to guide revascularization decisions in DM patients. We performed a single-center study of patients who underwent CABG. Patients with no DM were compared with patients with DM, subgrouped according to whether or not DM was treated with insulin before admission (Insulin and No Insulin Groups). Multivariable logistic regression was used to determine whether DM was a significant predictor of mortality, combined postoperative events, and specific postoperative complications after controlling for other predictive clinical variables. Of 11,590 consecutive patients who underwent CABG, 5,013 (43%) had DM and 6,577 (57%) had no DM. Of the patients with DM, 3,433 (68%) were not treated with insulin and 1,580 (32%) were treated with insulin before admission. Multivariable logistic regression analyses showed that DM was not significantly associated with in-hospital mortality or combined postoperative events after considering other clinical variables. The No Insulin Group was significantly associated with stroke, and the Insulin Group was significantly associated with surgical site infection and new renal failure. In conclusion, this study of consecutively treated CABG patients shows that DM is not a predictor of in-hospital mortality or combined in-hospital postoperative events after adjusting for other clinical factors. DM is a predictor of permanent stroke, surgical site infection, and new renal failure. These findings may help with case selection and management of DM patients undergoing CABG.