Elevated urinary Kidney Injury Molecule 1 (KIM-1) at discharge strongly predicts early mortality following an episode of acute decompensated heart failure

Abstract

INTRODUCTION Hospitalization for acute decompensation of heart failure (ADHF) is a frequent event associated with long-term adverse effects. Prognosis is even worse if acute kidney injury (AKI) occurs during hospitalization.OBJECTIVES The study aimed to determine whether kidney damage biomarkers neutrophil gelatinase--associatedlipocalin (NGAL), kidney injury molecule 1 (KIM-1), and interleukin 18 (IL-18) might predict AKI and have prognostic value in ADHF.PATIENTS AND METHODS Serum NGAL on admission and urine NGAL, KIM-1, and IL-18 on discharge were determined in 187 ADHF patients enrolled in a prospective, observational, unblinded study. AKI was diagnosed using the Kidney Disease: Improving Global Outcomes criteria. Patients were followed for 12 months to record all-cause mortality.RESULTS A total of 22% patients died during the follow-up, with 52.5% dying within 4 months after discharge. Serum NGAL (P <0.001), urine NGAL (P = 0.047), and urinary KIM-1 (P = 0.014) levels were significantly higher in the deceased patients at discharge. After adjustment for estimated glomerular filtration rate (eGFR), only urinary KIM-1 independently predicted mortality at month 4 (hazard ratio [HR], 3.166; 95% CI, 1.203-8.334; P = 0.020) and month 12 (HR, 1.969; 95% CI, 1.123-3.454; P = 0.018) in Cox regression models. In receiver operating characteristic (ROC) analysis urinary KIM-1 (area under the ROC curve [AUC] = 0.830) outperformed other markers of renal function. The Kaplan-Meier sur-vival analysis showed KIM-1 predictive value as additive to that of AKI incidence and admission eGFR. Admission serum NGAL was higher in AKI patients (P <= 0.001) with a modest diagnostic performance (AUC = 0.667), below that of urea (AUC = 0.732), creatinine (AUC = 0.696), or cystatin C (AUC = 0.676).CONCLUSIONS Discharge urinary KIM-1 was a strong and independent predictor of mortality, particularly during the most vulnerable period shortly after hospitalization. Admission serum NGAL was inferior to conventional renal function parameters in predicting AKI during ADHF.