Serial Measurements of Neutrophil Gelatinase-Associated Lipocalin levels for Assessment of Contrast Induced Nephropathy among Chronic Kidney Disease Patients Who Underwent Elective Coronary Angiography

Background: Among chronic kidney disease (CKD) patients, baseline neutrophil gelatinase-associated lipocalin (NGAL) may reflect the severity of renal impairment. No data exists on serial changes in serum NGAL levels in CKD patients before and after percutaneous coronary intervention (PCI). Objectives: To evaluate serial serum NGAL levels relation to contrast induced acute kidney injury (CI-AKI) following PCI. Methods: The study included 58 patients with CKD who underwent elective PCI. Plasma NGAL measurements were performed before (pre-NGAL) and 24 hours following (post-NGAL) PCI. Patients were followed for CI-AKI and changes in NGAL levels. Receiver operator characteristic identified the optimal sensitivity and specificity for pre-NGAL levels compared with post-NGAL for patients with CI-AKI. Results: Overall CI-AKI incidence was 33%. Both pre-NGAL (172 vs. 119 ng/ml, P< 0.001) and post-NGAL (181 vs. 121 ng/ ml, P< 0.001) levels were significantly higher in patients with CI-AKI, but no significant changes were detected. Pre-NGAL levels were similar to post-NGAL levels in predicting CI-AKI (area under the curve 0.753 vs. 0.745). Optimal cutoff value for pre-NGAL was 129 ng/ml (sensitivity of 7 3 % and specificity of 72%, P< 0.001). Post-NGAL levels > 141 ng/ml were independently associated with CI-AKI (hazard ratio [HR] 4.86, 9 5 % confidence interval [95%CI] 1.34-17.64, P = 0.02) with a strong trend for post-NGAL levels > 129 ng/ml (HR 3.46, 95%C11.23¬ 12.81, P= 0.06). Conclusions: In high-risk patients, pre-NGAL levels may predict CI-AKI. Further studies on larger populations are needed to validate the use of NGAL measurements in CKD patients.