Does microalbuminuria in diabetic patients affect the postoperative course after coronary artery bypass surgery?

OBJECTIVES: Microalbuminuria is a predictor of microvascular disease and a marker for multiorgan damage in diabetic patients. It has been proposed that in diabetic patients who would undergo coronary artery bypass surgery (CABG), microalbuminuria is associated with poor postoperative outcome, higher incidence of early and late morbidity and mortality. METHODS: Microalbuminuria was prospectively studied preoperatively in 24-h urinary collections for 257 consecutive diabetic patients in a 2-year period. One hundred and sixty-eight patients (65.4%) were defined as microalbuminuria negative (Group A), and 89 (34.6%) were microalbuminuria positive (Group B) with respect to the cut-off point 30 mg/24 h. RESULTS: The two groups did not differ with respect to preoperative and operative data, except that preoperative blood glucose levels (P=0.046), blood urea nitrogen (P=0.001), and creatinine (P=0.001) were higher and creatinine clearance was lower (P=0.025) in Group B. Postoperative serum creatinine levels on different days were higher in microalbuminuria positive patients (P=0.04). Also, positive inotropic agent usages at the time of leaving the operating room (21.3 vs. 10.1%; P=0.013) and on the 1st day in the intensive care unit (ICU; 29.2 vs. 14.9%; P=0.014), ICU stay day (2.3+/-2 vs. 2.4+/-1.6; P=0.02) and also atrial fibrillation rate (30.3 vs. 17.9%) were higher in Group B (P=0.019). Total hospital stay (7.5+/-2.9 vs. 7.2+/-1.3) was similar. The 30-day mortality was 5.6 times higher (3.4 vs. 0.6%) but statistically not significant (P=0.088) in Group B. The mean follow-up was 30.6+/-16. 2 months in total (30.9+/-16.2 in Group A and 30.1+/-16.5 in Group B). There were 12 late deaths, nine were cardiac, and no differences were detected between groups. CONCLUSIONS: Our findings suggest that postoperative period may be more problematic in diabetic patients with microalbuminuria, but microalbuminuria does not seem to have a major effect on the postoperative course in patients undergoing CABG.