Diabetes and coronary artery bypass surgery - An examination of perioperative glycemic control and outcomes

Objective - To determine the adequacy of perioperative glycemic control in diabetic patients undergoing coronary artery bypass grafting (CABG) and to explore the association between glycemic control and in-hospital morbidity/mortality. Research Design and Methods - Retrospective cohort study of consecutive patients with diabetes undergoing CABG between April 2000 and March 2001 who survived at least 24 h postoperatively. Results - Of the 291 patients in this study, 95% had type 2 diabetes and 40% had retinopathy, nephropathy, or neuropathy at baseline. During hospitalization (median 7 days), 78 (27%) of these patients suffered a nonfatal stroke or myocardial infarction, septic complication, or died ("adverse outcomes"). Glycemic control was suboptimal (average glucose on first postoperative day was 11.4 [11.2-11.6] mmol/l) and was significantly associated with adverse outcomes post-CABG (P = 0.03). Patients whose average glucose level was in the highest quartile on postoperative day 1 had higher risk of adverse outcomes after the first postoperative day than those with glucose in the lowest quartile (odds ratio 2.5 [1.1-5.3]). Even after adjustment for other clinical and operative factors, average blood glucose level on the first postoperative day remained significantly associated with subsequent adverse outcomes: for each 1-mmol/l increase above 6.1 mmol/l, risk increased by 17%. Conclusions - Perioperative glycemic control in our cohort of diabetic patients undergoing CABG in a tertiary care facility was suboptimal. We believe closure of this care gap is imperative, because hyperglycemia in the first postoperative day was associated with subsequent adverse outcomes in our study patients.