Neutrophil Gelatinase-Associated Lipocalin as a Marker for Contrast-Induced Nephropathy in Patients Undergoing Percutaneous Coronary Intervention: A Prospective Observational Analysis.

Introduction: Incidence of contrast-induced nephropathy (CIN) post percutaneous coronary intervention (PCI) varies between 5% and 20%. Neutrophil gelatinase-associated lipocalin (NGAL) is a sensitive marker for acute kidney injury. Data regarding the predictive accuracy of NGAL in Indian patients undergoing PCI is sparse. Methods: A total of 212 consecutive "all-comer" patients, undergoing PCI from March 2015 to April 2016 were recruited in this single-center observational study. Plasma NGAL levels were measured at 4 hours post PCI using commercially available enzyme-linked immunosorbent assay (Triage® Alere™, San Diego, CA, USA). Results: Twenty-five (11.8%) patients developed CIN. The 4-hour post-PCI plasma NGAL levels were significantly higher in patients with CIN than without (400.6 ± 269.3 ng/mL vs. 109.8 ± 68.0 ng/mL, P < 0.0001). Patients developing CIN had higher age, low estimated glomerular filtration rate (eGFR), and higher contrast volume usage during PCI. After adjusting for confounding factors, diabetes mellitus (adjusted odds ratio [AOR] 3.04; P = 0.039; 95% confidence interval [CI]: 1.06-8.73), hypotension at presentation (AOR 24.84; P < 0.0001; 95% CI: 4.65-132.83), and multi-staged PCI (AOR 13.45; P < 0.0001; 95% CI: 4.54-39.79) were found to independently predict the development of CIN. NGAL levels significantly correlated with age (r = 0.149, P = 0.031), eGFR (r = -0.385, P < 0.0001), hemoglobin (r = -0.214, P = 0.002), contrast volume (r = 0.185, P = 0.007), and 48-hour post-PCI serum creatinine levels (r = 0.334, P < 0.0001). At a cutoff of 256.5 ng/mL, plasma NGAL had a sensitivity of 68% and a specificity of 95.2% (area under the curve = 0.878; P < 0.0001; 95% CI: 0.801-0.955) to predict the occurrence of CIN. Conclusions: Plasma NGAL is an early and highly predictive biomarker of CIN in patients undergoing PCI. Patients having diabetes, hypotension at presentation and those undergoing second-stage procedures are at a high risk of developing CIN after PCI.