ABSTRACT
BACKGROUND: Diabetes mellitus is associated with poorer long-term outcomes following coronary artery bypass graft (CABG) surgery. However, little is known about the impact of diabetes mellitus on outcomes during the first 12 months following CABG. OBJECTIVES: To examine the relationship between diabetes mellitus and outcomes during the 12 months following CABG. METHODS: The Routine versus Selective Exercise Treadmill Testing after Coronary Artery Bypass Grafting (ROSETTA-CABG) Registry is a prospective, multicentre study examining the use of functional testing after CABG surgery. A total of 398 patients who were enrolled in the ROSETTA-CABG Registry were examined. Diabetic status was defined by medication use at discharge. Only patients undergoing a first successful CABG (all ischemic areas thought to be revascularized) were included. RESULTS: Among the 398 patients, 37 (9.3%) were receiving insulin, 67 (16.8%) were receiving oral hypoglycemic agents, and 294 (73.9%) were not receiving insulin or oral hypoglycemic agents. Insulin-treated patients had a higher 12-month incidence of composite clinical events consisting of readmission for unstable angina, myocardial infarction or death than did oral hypoglycemic-treated patients and nondiabetic patients (21.6% versus 4.5% and 6.0%, respectively; P=0.0003). Insulin-treated patients were also more likely to undergo repeat cardiac catheterization than were oral hypoglycemic-treated patients and nondiabetic patients (18.9% versus 8.8% and 7.9%, respectively; P=0.03). After controlling for other variables, use of insulin was independently associated with a composite of adverse clinical events (OR 3.80, 95% CI 1.5 to 9.6, P=0.005). CONCLUSIONS: During the 12-month period after a successful CABG, insulin-treated patients had a higher rate of adverse cardiac events than did patients receiving oral hypoglycemic agents and nondiabetic patients. These results suggest that diabetic patients may benefit from more aggressive surveillance during the first year after CABG surgery.
