The influence of
diabetes mellitus and complications on the long-term outcome of
coronary artery bypass graft surgery (CABG) was investigated in 192 consecutive patients who underwent elective CABG between January 1992 and March 1996. Of these, 102 patients were diabetic and 90 were nondiabetic. Preoperative and postoperative left ventricular ejection fraction, number of grafts, use of arterial conduit, and frequency of perioperative
infarction were all similar in the 2 groups. During a mean follow-up of 3.2 years, diabetics showed higher cardiac mortality than nondiabetics (15% vs 3%, p = 0.01).
Cardiac event-free survival was also low in diabetics, and this difference increased throughout the period (91% vs 99% at 2 years, 74% vs 90% at 4 years in diabetics and nondiabetics, respectively, by Kaplan-Meier analysis, p = 0.008). Multivariate Cox regression analysis revealed postoperative low ejection fraction and
diabetes mellitus as independent predictors of late
cardiac death. Major causes of
cardiac death in diabetics were
sudden death, pump failure and acute
myocardial infarction. Additionally, subgroup analysis in diabetics using the Cox regression model identified postoperative low ejection fraction, female gender and
diabetic nephropathy as independent predictors of late
cardiac death. Thus, patients with diabetes have a worse clinical outcome after CABG, especially when associated with low ejection fraction, female gender and
diabetic nephropathy. Intensive management of
heart failure, prevention of
myocardial infarction and specific strategy for female patients are all essential to improve the long-term outcome of diabetics after CABG.