OBJECTIVETo investigate the incidence and risk factors of acute kidney injury (AKI) within the first postoperative week after off-pump or on-pump coronary artery bypass (OPCAB or CCAB) surgery.

METHODSConsecutive patients underwent CABG between January 1990 and August 2006 in our institution and had normal serum creatinine (Scr) and estimated creatinine clearance (Ccr) values before operation were retrospectively analyzed. Multivariate logistic regression analysis was performed to identify risk factors for the development of AKI defined as Scr 130 - 199 micromol/L or Ccr 30 - 60 mlxmin(-1)x1.73 m(-2).

RESULTSIncidence of AKI was significantly higher in patients underwent CCAB compared to those underwent OPCAB (63/331 vs. 61/518, P < 0.01). Peak Scr value was seen at 12th hour post OPCAB and 24th hour post CCAB, respectively. The rapid recovering of Scr occurred between 24th hour to 48th hour in patients underwent OPCAB and 48th hour to 72th hour in patients underwent CCAB surgery. Multivariate forward stepwise logistic regression analysis showed that LVEF < 30%, pulse pressure >/= 60 mm Hg (1 mm Hg = 0.133 kPa), peripheral vascular disease, diabetes, emergent procedure, triple-vessel disease, higher body mass index (kg/m(2)), intraoperative and postoperative IABP, NYHA class III or IV and cardiopulmonary bypass were risk factors for the development of postoperative AKI following CABG, while LVEF > 50% and intraoperative and postoperative IABP were associated with lower incidence of AKI (OR < 1).

CONCLUSIONAKI is not a rare complication post OPCAB or CCAB surgery, especially in patients with reduced LVEF, increased pulse pressure, peripheral vascular disease, diabetes, emergent procedure, triple-vessel disease, higher body mass index, intraoperative and postoperative IABP.