N-acety-b-D-glucosaminidase: A potential biomarker for early detection of acute kidney injury in acute chest pain.

AIM: Acute kidney injury (AKI) is often underdiagnosed due to several limitations of the renal marker creatinine. Tubular urinary biomarkers may substantially contribute to diagnose AKI early. For early detection of AKI, we evaluated for the first time N-acetyl-ß-d-glucosaminidase (NAG), Kidney-injury-molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) in acute chest pain. METHODS: We included 402 chest pain patients aged 18 to 95 years seen in the emergency department. From 311 subjects, blood and urine samples were collected. RESULTS: Thirty-three patients developed an AKI and showed a significant increase in all three tubular markers compared to patients without AKI (each P < .001). According to receiver operating characteristic (ROC) analysis, combining NAG and creatinine showed a significantly increased area under the curve (AUC) compared to creatinine alone (AUC: 0.75 vs 0.87; P < .001). KIM-1, NGAL and cystatin C showed no significant differences in AUC compared to creatinine. In 120 individuals with blood and urine sampling before contrast media exposure, ROC analysis showed a significantly improved diagnostic performance for the combination of both (AUC: 0.83 vs creatinine AUC: 0.66; P = .004). AKI occurrence showed no dependency from CM volume. NAG presented as an independent AKI predictor beside creatinine, age, the diagnosis of myocardial infarction and mean arterial pressure. Regarding the prognostic value for renal replacement therapy, the combination of NAG and creatinine showed a significantly lager AUC than creatinine (AUC: 0.95 vs AUC: 0.85; P < .001). CONCLUSION: NAG presented as a promising marker of impending AKI and the necessity of renal replacement therapy.

Urinary N-terminal pro-brain natriuretic peptide: prognostic value in patients with acute chest pain.

AIMS: The objective of this study was to investigate the prognostic value of urinary N-terminal pro-brain natriuretic peptide (NT-proBNP) compared with plasma NT-proBNP in patients presenting with acute chest pain in the emergency department. METHODS AND RESULTS: We measured simultaneously plasma and urinary NT-proBNP at admission in 301 patients with acute chest pain. In our cohort, 174 patients suffered from acute coronary syndrome (ACS). A follow-up (median of 55 months) was performed regarding the endpoints all-cause mortality and major adverse cardiac events (mortality, congestive heart failure, ACS with the necessity of a coronary intervention, and stroke). Fifty-four patients died during follow-up; 98 suffered from the combined endpoint. A significant and positive correlation of urinary and plasma NT-proBNP was found (r = 0.87, P < 0.05). Patients with troponin positive ACS had significantly elevated levels of plasma and urinary NT-proBNP compared with those with unstable angina pectoris or chest wall syndrome (each P < 0.05). The highest levels of both biomarkers were found in patients with congestive heart failure (each P < 0.05). According to Kaplan-Meier analysis, plasma and urinary NT-proBNP were significant predictors for mortality and the combined endpoint in the whole study cohort and in the subgroup of patients with ACS (each P < 0.05). Regarding Cox regression analysis, plasma and urinary NT-proBNP were independent predictors for mortality and the combined endpoint (each P < 0.05). CONCLUSIONS: Urinary NT-proBNP seems to provide a significant predictive value regarding the endpoints all-cause mortality and major adverse cardiac events in patients with acute chest pain and those with ACS.

The role of the tubular biomarkers NAG, kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin in patients with chest pain before contrast media exposition.

Aim: We evaluated the role of the tubular biomarkers N-acetyl-ß-D-glucosaminidase (NAG), kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) in patients with chest pain. Methods: Serum and urine samples were collected of 223 patients and 47 healthy controls. None of them was exposed to contrast media. Results: NAG showed among others significant correlation with N-terminal pro brain natriuretic peptide (NTproBNP), troponin I and creatinine. KIM-1 and NGAL showed weaker correlations. NAG was significantly elevated in all subgroups of acute coronary syndrome (ACS) compared with chest wall syndrome and controls. NAG was an independent predictor for the diagnosis of myocardial infarction. Conclusion: NAG may demonstrate the presence of acute tubular injury due to cardiac impairment already in the emergency department. NAG should be evaluated as marker of acute cardiorenal syndrome in patients with chest pain.