[The value of urinary neutrophil gelatinase-associated lipocalin for early diagnosis of contrast-induced nephropathy].

To explore the value of urinary neutrophil gelatinase-associated lipocalin (NGAL) for early diagnosis of contrast-induced nephropathy (CIN) in patients who underwent percutaneous coronary angiography (CAG) or percutaneous coronary intervention (PCI). From May 2015 to January 2016, 506 consecutive patients who underwent CAG or PCI in our hospital were enrolled in this prospective study. Patients were divided into CIN group (=47) and non-CIN group (=459). Clinical and interventional data were compared between the two groups. Spearman ranking correlation coefficient was used to define the relation between NGAL and CIN, and multivariable logistic regression analysis was performed to identif independent predictors of CIN. Receiver-operator characteristic (ROC) curve was generated, and area under the curve (AUC) was calculated and sensitivity and specificity for CIN diagnosis were analyzed. (1) Basic clinical and interventional data including age, incidence of diabetes, hypertension and chronic heart failure, level of systolic blood pressure, serum creatine before procedure, use of isotonic contrast agent, contrast volume, Mehran score, operation time, treatment number of coronary artery, hydration and medication were all similar between two groups (all >0.05). (2) Urinary NAGL level at 24 and 48 h after procedure, serum creatinine (Scr) level at 48 h after procedure, and ΔNGAL were significantly higher in CIN group than in non-CIN group (all <0.01), but the differences of urinary NGAL level before procedure, Scr level 24 h after procedure, and ΔNGAL were similar between two groups (all >0.05). (3)The positive correlation was found by Spearman ranking correlation between ΔNGAL and CIN (=0.478, <0.001). (4) Multivariable logistic regression analysis showed that estimated glomerular filtration rate(=1.020, 95% 1.005-1.035, =0.007) and ΔNGAL (=1.020, 95% 1.014-1.027, <0.001) were the independent predictors of CIN.(5) ROC curve showed that the AUC of NGAL with the cutoff value 4.65 was 0.899(0.854, 0.944)for diagnosis of CIN (sensitivity 93.6%, and specificity 0.944). The rise of urinary NGAL level at 24 and 48 hours after CAG or PCI is suggestive of CIN and could be used as a reliable parameter for the early diagnose of CIN.