Renal Outcome In Off-Pump Coronary Artery Bypass Grafting: Predictors For Renal Impairment With Multivariate Analysis

Objective: Recent studies on the efficacy of off-pump coronary artery bypass grafting (OPCABG) have reported encouraging results on postoperative renal function, but improvements can still be made.Methods: A total of 368 patients, none needing chronic dialysis, underwent isolated OPCABG at our institution between January 1999 and March 2005. They were divided into 3 groups according to renal function as indicated by the serum creatinine levels: group N (n = 332) with normal function, group M (n = 30) with mild to moderate renal dysfunction, and group S (n = 6), with severe renal dysfunction. Creatinine ratio and early outcomes were compared among the groups. Predictors for renal impairment were determined by multiple regression analysis.Results: In-hospital mortality rate was similar (group N, 0.6%; group M, 0%; group S, 0%). The percentage of patients with a creatinine ratio greater than 1.6 was significantly larger in group S (group N, 13%; group M, 13%; group S, 50%; P < 0.05). Postoperative hemodialysis, which was temporary, was required more frequently in group S (group N, 0.3%; group M, 3%; group S, 67%; P < 0.05). In group N, 38 patients (11%) had new renal impairment after OPCABG. Preoperative serum creatinine levels >= 2.5 mg/dL, ejection fraction <0.4, amount of blood transfusion, and more than 4 bypasses were potent predictors for postoperative renal impairment.Conclusions: Clinical results of OPCABG on renal function were satisfactory regardless of preoperative renal function. However, perioperative renal function should be closely monitored in patients with known risk factors, even when OPCABG is performed.