Neutrophil gelatinase-associated lipocalin (NGAL) for the early detection of contrast-induced nephropathy after percutaneous coronary intervention.

BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) occurs in up to 13% of patients undergoing percutaneous coronary intervention (PCI). Neutrophil gelatinase-associated lipocalin (NGAL) is an early biomarker for renal impairment. We investigated whether increased urinary NGAL concentrations were predictive of CI-AKI within 2 days after PCI or of a higher re-hospitalization rate within 9 months.

METHODS: Consecutive patients (n = 128), with stable coronary heart disease and eGFR ≥ 30 mL/min/1.73 m(2), undergoing PCI were included. Venous serum samples for measurement of creatinine, blood urea nitrogen, and cystatin C and urine samples for NGAL measurement were collected 4 hours and 1 and 2 days after contrast medium application. Patients were followed over 9 months to determine clinical endpoints.

RESULTS: CI-AKI was observed in 14 patients (10.9%) after PCI. NGAL concentrations before PCI were significantly higher in patients with subsequent CI-AKI (19.8 ng/mL [14.4-35.8] vs. 11.6 ng/mL [5.6-28.2]; p = 0.04). There was no significant difference in NGAL concentrations 4 h after PCI between patients with and without CI-AKI. One day after PCI, NGAL concentrations were significant higher in patients developing CI-AKI (100.1 ng/mL [41.5-129.2] vs. 16.6 ng/mL [9.1-28.1]; p < 0.001). Compared to common biomarkers, NGAL best predicted CI-AKI (AUC 0.939 [95% CI 0.89-0.99; p < 0.001]). The re-hospitalization rate due to progressive renal insufficiency within 9 months was higher in the group with CI-AKI than the group without (4 [28.6%] vs. 4 [3.5%], p < 0.01).

CONCLUSION: Urinary NGAL is a biomarker for predicting CI-AKI when measured 1 day after PCI.