492 Urinary NGAL is not Associated With Renal Function Changes or Hospitalization in Ambulatory Heart Failure Patients

Abstract

Urinary neutrophil gelatinase-associated lipocalin (NGAL) has been shown to be an early predictive biomarker for acute kidney injury and serves as a surrogate for injury to renal tubules. Renal function deteriorations are common in CHF yet it remains unclear whether renal tubular injury is involved. Further if renal tubular injury occurs it is unclear whether declines in GFR lead to tubular injury or vice versa. We set out to investigate changes in urinary NGAL and the temporal relationship with GFR changes and hospitalization. Patients with an LVEF < 40% were prospectively followed in a tertiary care heart failure clinic for up to 24 months (median 333 days (IQR 192-457). Laboratory values and clinical outcomes were measured every 3 months. Mixed linear and ordinary linear regression models with sandwich estimators were employed to determine the relationship between changes in urinary NGAL and changes in renal function change and hospitalization. Urinary NGAL was measured by ELISA. A total of 140 patients (83% male, mean EF 24.8±7.0%) were enrolled during the study period. Changes in urinary NGAL were not associated with hospitalization (p=0.2). Increases in NGAL were not associated with a subsequent decline in eGFR (p=0.1) nor vice versa, declines in eGFR associated with increases in subsequent urinary NGAL (p=0.5). Urinary NGAL, a promising biomarker of renal tubular injury in acute kidney injury, is not associated with changes in eGFR or hospitalization in an ambulatory heart failure population.