Indexed neutrophil gelatinase associated lipocalin: a novel biomarker for the assessment of acute kidney injury.

INTRODUCTION: Acute kidney injury (AKI) is a clinically relevant and common complication among patients with acute coronary syndrome. Neutrophil gelatinase-associated lipocalin (NGAL), secreted from different cells including renal tubules, has been widely studied as an early marker for kidney injury. However, chronic kidney disease (CKD) could impact NGAL levels and alter their predictive performance. Some studies attempted to address this issue by setting different cutoff values for patients with CKD, with limited success to date. Our aim was to evaluate a novel estimated glomerular filtration rate (eGFR)-adjusted "indexed NGAL" and its ability to predict in-hospital AKI among patients with ST elevation myocardial infarction. METHODS: We performed a prospective, observational, single center study involving patients with ST elevation myocardial infarction admitted to the coronary intensive care unit. Serum samples for baseline NGAL were collected within 24 h following hospital admission. The eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. In-hospital AKI was determined as occurring after ≥ 24 h from admission. To perform an individualized adjustment, we used the result of 24 h NGAL divided by the eGFR measured upon admission to the hospital (Indexed-NGAL; I-NGAL). RESULTS: Our cohort includes 311 patients, of whom 123 (40%) had CKD, and 66 (21%) suffered in-hospital AKI. NGAL levels as well as I-NGAL levels were significantly higher in patients with AKI (136 vs. 86, p < 0.01 and 3.13 VS. 1.06, p < 0.01, respectively). Multivariate analysis revealed I-NGAL to be independently associated with AKI (OR 1.34 (1.10-1.58), p < 0.01). I-NGAL had a higher predictive ability than simple NGAL results (AUC-ROC of 0.858 vs. 0.778, p < 0.001). CONCLUSION: Adjusting NGAL values according to eGFR yields a new indexed NGAL value that enables better prediction of AKI regardless of baseline kidney function.

Predictive value of elevated neutrophil gelatinase-associated lipocalin levels for assessment of in-hospital adverse outcomes among myocardial infarction patients.

BACKGROUND: Inflammatory biomarkers are known to rise and have predictive value for adverse outcomes in patients with acute coronary ischemia. One of those biomarkers is neutrophil gelatinase-associated lipocalin (NGAL). To date, only very few studies have assessed the prognostic value of NGAL in this setting. We investigated the prognostic utility of elevated NGAL levels on clinical outcomes among ST-elevation myocardial infarction patients. METHODS: High NGAL was defined as values within the 4th quartile. Patients were assessed for major in-hospital adverse clinical events (MACE). Multivariable logistic regression and area under the receiver operating characteristic curve (AUC) were used to further evaluate NGAL association for MACE and discrimination ability. RESULTS: A total of 273 patients were included. patients with high NGAL were at increased risk for MACE (62% vs. 19%; odds ratio 6.88, 95% confidence interval, 3.77-12.54, P  < 0.001). After propensity score matching, the incidence of MACE was significantly higher in patients with high vs. low NGAL levels (69% vs. 6%, P  = 0.002). In multivariable regression, high NGAL level was independently associated with MACE. The discrimination ability of NGAL to identify MACE (AUC 0.823), is significantly better than that of other inflammatory markers. CONCLUSION: Among ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention, high NGAL levels are associated with adverse outcomes, independent of traditional inflammatory markers.

Biomarker-Guided Assessment of Acute Kidney Injury Phenotypes E among ST-Segment Elevation Myocardial Infarction Patients.

Recent practice guidelines recommended the use of new stress, functional, and damage biomarkers in clinical practice to prevent and manage acute kidney injury (AKI). Biomarkers are one of the tools used to define various AKI phenotypes and provide prognostic information regardless of an acute decline in renal function. We investigated the incidence and possible implications of AKI phenotypes among ST elevation myocardial infarction patient treated with primary coronary intervention. We included 281 patients with STEMI treated with PCI. Neutrophil gelatinase associated lipocalin (NGAL) was utilized to determine structural renal damage and functional AKI was determined using the KDIGO criteria. Patients were stratified into four AKI phenotypes: no AKI, subclinical AKI, hemodynamic AKI, and severe AKI. Patients were assessed for in-hospital adverse events (MACE). A total of 46 patients (44%) had subclinical AKI, 17 (16%) had hemodynamic AKI, and 42 (40%) had severe AKI. We observed a gradual and significant increase in the occurrence of MACE between the groups being highest among patients with severe AKI (10% vs. 19% vs. 29% vs. 43%; p < 0.001). In a multivariable regression model, any AKI phenotype was independently associated with MACE with an odds ratio of 4.15 (95% CI 2.1−8.3, p < 0.001,) for subclinical AKI, 4.51 (95% CI 1.61−12.69; p = 0.004) for hemodynamic AKI, and 12.9 (95% CI 5.59−30.1, p < 0.001) for severe AKI. In conclusion, among STEMI patients, AKI is a heterogeneous condition consisting of distinct phenotypes, addition of novel biomarkers may overcome the limitations of sCr-based AKI definitions to improve AKI phenotyping and direct potential therapies.