A Comparison of Urinary Neutrophil Gelatinase-Associated Lipocalin in Patients Undergoing On- Versus Off-Pump Coronary Artery Bypass Graft Surgery

ObjectiveThe purpose of this study was to compare urinary neutrophil gelatinase-associated lipocalin (NGAL) levels in off-pump and on-pump coronary artery bypass graft (CABG) surgery.DesignA matched cohort study.SettingA tertiary university hospital.ParticipantsThirty adult patients undergoing CABG surgery without cardiopulmonary bypass (off-pump) matched to 30 patients with on-pump CABG surgery by age, preoperative serum creatinine, Parsonnet score, ejection fraction, body mass index, and number of coronary artery grafts.InterventionsNone, observational.Measurements and Main ResultsUrinary NGAL, a novel, highly sensitive biomarker for renal injury, was measured before and immediately after surgery and then 3, 18, and 24 hours later. There were no differences in urinary NGAL at any time point between patients subjected to off-pump or on-pump CABG surgery; the peak urinary NGAL in patients who underwent off-pump CABG surgery was 94.7 ± 30.9 ng/mL compared with 122.7 ± 57.0 ng/mL in patients with on-pump CABG surgery (p = 0.6). Peak serum creatinine and the incidence of acute kidney injury also were not different between the groups.ConclusionsUrinary NGAL was not different in patients undergoing off-pump and on-pump CABG surgery despite a very good match between the groups with respect to pre- and intraoperative risk factors.