On-Pump Versus Off-Pump Coronary Artery Bypass Grafting in Diabetic Patients: A Propensity Score Analysis

Background Diabetic patients are recognized as being at high risk for adverse outcomes after coronary artery bypass grafting. We evaluated our outcomes in diabetic patients to compare the effect of off-pump with on-pump coronary revascularization. Methods Between April 1997 and September 2002, 951 consecutive diabetic patients underwent isolated coronary artery bypass grafting. A total of 186 (19.6%) of these patients had off-pump coronary procedures. Multivariate logistic regression was used to assess the effect of off-pump coronary procedures on adverse in-hospital outcomes, while adjusting for patient and disease characteristics by constructing a propensity score from core patient characteristics. The propensity score was the probability of receiving off-pump coronary operation, with a C-statistic of 0.81, and was included along with the comparison variable in a multivariable analysis of outcome. All analysis was performed retrospectively. Results Off-pump patients were more likely to be obese (p = 0.032), have left main stem stenosis (p = 0.034), and have undergone prior cardiac operation (p = 0.027). The off-pump group had fewer patients with three-vessel disease compared with the on-pump group. After risk adjusting with propensity score, off-pump patients had a significantly lower incidence of stroke (adjusted odds ratio 0.15; p = 0.039) and renal failure (adjusted odds ratio 0.38; p = 0.036). Off-pump patients also required less blood transfusion (p< 0.001) and had shorter lengths of stay (p< 0.001). Conclusions Off-pump coronary operation in diabetic patients significantly reduced postoperative morbidity and length of stay compared with on-pump coronary operation, although no in-hospital survival difference was noted between the two groups.