A prospective randomized study to evaluate the renal impact of surgical revascularization strategy in diabetic patients

Acute kidney injury (AKI) is a major postoperative complication following cardiac surgery. Diabetes mellitus is a major cause of nephropathy and end-stage renal failure. We aimed to evaluate the occurrence of adverse renal outcomes, in diabetic patients, between on-pump (CPB) and off-pump (OPCAB) coronary artery bypass graft (CABG). Seventy-one diabetic patients (36 and 35 patients in the CPB and OPCAB groups, respectively) were enrolled in a prospective randomized study. Renal tubular and glomerular functions, were monitored preoperatively and over five consecutive days. There was no significant difference between the groups in terms of age, gender, New York Heart Association class, Canadian Cardiovascular Society functional classification of angina grade and number of CABG. Intensive care unit stay, duration of intubation, hospital stay and bleeding were significantly higher in the CPB group. No significant differences in plasmatic creatinine, urinary creatinine, creatinine clearance, proteinuria or osmolality were detected. A significant rise in urinary albumine excretion occurred in both groups peaking on the operative day; for the on-pump CABG group (10±5 vs. 48±57; P=0.015) and for the OPCAB group (11±6 vs. 37±59; P=0.04). Values were less important in the OPCAB group and return to the baseline was faster than in the CPB group. OPCAB attenuates sub-clinical AKI, in diabetic patients.