Neutrophil Gelatinase-Associated Lipocalin (NGAL) in Predicting Worsening Renal Function in Acute and Chronic Heart Failure

Background: The development of worsening renal function (WRF, defined as serum creatinine rise ?0.3 mg/dL) occurs frequently in the setting of acute decompensated heart failure (ADHF) and strongly predicts adverse clinical outcomes. NGAL has emerged as promising and sensitive biomarker of early AKI in a diverse range of settings, as NGAL rapidly appears in both blood and urine in response to renal tubular damage. Renal insufficiency as assessed by a reduction in estimated glomerular filtration rate (eGFR) is frequently observed in patients with chronic heart failure(CHF) and is associated with reduced survival. Objective: To assess the role of serum NGAL in predicting subsequent development of WRF in case of ADHF and as a diagnostic marker for renal impairment in CHF and to establish the relationship between serum NGAL and other renal parameters (BUN, creatinine and eGFR). Methods: Our study included 30 patients with chronic HF (group I), 30 patients with acute HF (group II) and 20 subjects; age and sex matched apparently healthy individuals as controls (groupIII). All subjects gave informed written consent to participate in the study. All subjects were subjected to full history taking, complete clinical examination, chest x-ray, ECG, Echocardiography and laboratory investigations including CBC, BUN and serum creatinine, eGFR and serum NGAL level. In acute HF group; samples for NGAL assay were obtained at admission and on 3rd day, while changes in BUN, serum creatinine and eGFR were monitored during their hospital stay for 3 days to assess WRF. Results: BUN, serum creatinine and NGAL levels were significantly higher, while eGFR values were significantly lower in chronic HF cases as compared with their controls. A ROC curve analysis was performed to evaluate the individual diagnostic values of serum NGAL, creatinine and BUN for renal impairment in chronic HF cases. An optimal NGAL cutoff at >18?g/L, yielding 93% sensitivity and 76% specificity with area under curve (AUC) of 0.912. While BUN and serum creatinine had AUC of 0.625 and 0.729 respectively. In acute HF group, BUN, Serum creatinine and NGAL levels on admission were significantly higher, while, eGFR values were significantly lower in acute HF cases as compared with their controls. Also, BUN, serum creatinine and NGAL levels were significantly higher, while eGFR values were significantly lower in acute HF cases with WRF than their levels in cases without WRF at admission and on 3rd day. A ROC curve analysis was performed to evaluate predictive values of admission NGAL, creatinine and BUN for WRF in acute HF. An optimal admission NGAL cutoff at > 27.5?g/L yielding 90% sensitivity and 68% specificity with AUC 0.969. While BUN and serum creatinine had AUC of 0.569 and 0.684 respectively. Conclusion: NGAL can be considered as a sensitive diagnostic marker superior to both BUN and creatinine for early detection of impaired renal function in HF even before eGFR is markedly reduced.