Neutrophil gelatinase-associated lipocalin (NGAL) for the early detection of cardiac surgery associated acute kidney injury

Abstract

Background. Acute kidney injury (AKI) is a common complication after cardiac surgery. Neutrophil gelatinase-associated lipocalin (NGAL) may be an early biomarker for cardiac surgery–associated (CSA) AKI. We investigated whether increased urinary NGAL concentrations were predictive of AKI within 4 days after surgery and of mortality within 9 months. Methods. Consecutive patients (n = 141) undergoing major cardiac surgery were included. Creatinine, blood urea nitrogen, cystatin C and urinary NGAL were measured before, 4 hours and 4 days after extracorporeal circulation. Results. AKI was observed in 47 (33.3%) patients. The 4-hour urinary NGAL measurement was an independent predictor of stage 2 and 3 AKI (AUC 0.901; 95% CI 0.81–0.99). Patients with AKI had a higher 9-month mortality rate (19.1% vs. 3.2%; logrank 10.9; P = 0.001; HR 19.8; 95% CI 3.7–107.1). Urinary NGAL was not predictive of mortality within 9 months after surgery. Conclusion. Urinary NGAL is a biomarker for very early risk stratification of AKI after cardiac surgery and may be useful as a basis for early interventional strategies to prevent CSA-AKI.

Key Words::

• Major cardiac surgery
• extracorporeal circulation
• acute renal failure
• neutrophil gelatinase-associated lipocalin
• LCN2

Declaration of interest: All other authors declare that they have no conflict of interest with this study. The NGAL and Cystatin C assays were donated by Abbott. The funding sources were not involved in the design of the trial, the gathering, analysis and interpretation of data, the writing of the manuscript or the decision to publish the paper.