Fc 051predictive value of plasma ngal:hepcidin-25 for major adverse kidney events after cardiac surgery with cardiopulmonary bypass: a pilot study

Abstract Background and Aims Neutrophil gelatinase-associated lipocalin (NGAL) and hepcidin-25 appear to be involved in catalytic iron-related kidney injury after cardiac surgery with cardiopulmonary bypass. We aimed to explore the predictive value of plasma NGAL, plasma hepcidin-25, and the plasma NGAL:hepcidin-25 ratio for major adverse kidney events after cardiac surgery. Method We compared the predictive value of plasma NGAL, hepcidin-25, and NGAL:hepcidin-25 with those of serum creatinine (Cr), and urinary output and urinary protein for primary endpoint major adverse kidney events (MAKE; acute kidney injury [AKI] stages 2 and 3, persistent AKI > 48 hrs, acute dialysis, and in-hospital mortality) and secondary-endpoint AKI in 100 cardiac surgery patients at intensive care unit (ICU) admission. We performed ROC curve, logistic regression, and reclassification analyses. Results At ICU admission, plasma NGAL, plasma NGAL:hepcidin-25, and Cr predicted MAKE (area under the ROC curve [AUC]: 0.77 [95% confidence interval (CI) 0.60–0.94], 0.79 [0.63–0.95], 0.74 [0.51–0.97]) and AKI (0.73 [0.53–0.93], 0.89 [0.81–0.98], 0.70 [0.48–0.93]). For AKI prediction, NGAL:hepcidin-25 had a higher discriminatory power than Cr (AUC difference 0.26 [95% CI 0.00–0.53]). Urinary output and protein, plasma lactate, C-reactive protein, creatine kinase myocardial band, and brain natriuretic peptide did not predict MAKE or AKI (AUC < 0.70). Only plasma NGAL:hepcidin-25 correctly reclassified patients for MAKE or AKI (category-free net reclassification improvement: 0.82 [95% CI 0.12–1.52], 1.03 [0.29–1.77]). After adjustment to the Cleveland risk score, plasma NGAL:hepcidin-25 ≥ 0.9 independently predicted MAKE (adjusted odds ratio 16.34 [95% CI 1.77–150.49], P = 0.014), whereas Cr did not. Conclusion NGAL:hepcidin-25 is a promising plasma marker for predicting postoperative MAKE.