Long-term postoperative mortality in diabetic patients undergoing major non-cardiac surgery

The prognosis of diabetic patients after surgery remains controversial. Some suggest that the rates of death and complications today are almost identical in diabetic and non-diabetic patients within hospital stay or for 30 days postoperatively, whereas others suggest that diabetes still constitutes a major risk factor for both short-term (< or = 30 days) and long-term (> 30 days) patients especially after major cardiac surgery. We examined the long-term postoperative mortality of diabetic patients undergoing major non-cardiac surgery to identify possible perioperative risk factors.

Data from 179 consecutive diabetic patients, who underwent major non-cardiac surgery at Herlev Hospital, Denmark, during a 12 month period, have been retrospectively analysed. Data were obtained from patient records and from The Danish National Health Register. The main outcome measure was postoperative mortality. Patients were followed for a maximum of 18 months.

The median postoperative observation period was 10 months (range 0-18 months). Overall postoperative mortality was 24% (95% confidence interval (CI) 17-31%). One third of the fatalities occurred during the first 30 days. Ischaemic heart disease diagnosed before the operation was associated with an overall postoperative mortality of 44% (95% CI 29-58%), which was significantly (P < 0.03) higher than in diabetic patients without known cardiovascular disease. The major causes of death in 18 out of 39 (46%) patients were diseases of the cardiovascular system.

Diabetic patients undergoing major non-cardiac surgery seem to have a high mortality, often because of cardiovascular death. Future strategies should focus on implementing cardio-protective treatment during the perioperative period.