Novel Urinary Biomarkers in Detecting Acute Kidney Injury, Persistent Renal Impairment, and All-Cause Mortality Following Decongestive Therapy in Acute Decompensated Heart Failure

Background: New urinary biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18), are proposed to allow a more reliable early diagnosis and prognosis of acute kidney injury (AM) in acute decompensated heart failure (ADHF). Our aim was to compare the predictive value of urinary NGAL, KIM-1, and IL-18 for the occurrence of AM, persistent renal impairment, and mortality in ADHF. Methods and Results: Eighty-three patients admitted for ADHF were analyzed. Urinary creatinine (Cr), NGAL, KIM-1, and IL-18 were measured at baseline. Serum Cr was measured daily during the next 4 days and again at outpatient follow-up after 6 months. Mortality data were prospectively collected. Urinary NGAL, KIM-1, and IL-18 were modestly correlated with each other (Spearman rho <= 0.61) and poorly correlated with estimated glomerular filtration rate (eGFR; Spearman rho <= 0.28). None predicted AM, defined as a 25% decrease in eGFR, during the index hospitalization, but urinary IL-18/Cr was the strongest predictor of persistently elevated serum Cr >= 0.3 mg/dL after 6 months compared with baseline (area under the receiver operating characteristic curve 0.674; P = .013). Urinary IL-18 was also significantly associated with all-cause mortality (hazard ratio 1.48, 95% confidence interval 1.16-1.87; P = .001). Conclusions: Like urinary NGAL, urinary KIM-1 and IL-18 are relatively modest predictors of AM in ADHF. Among these novel renal biomarkers examined, further investigations regarding the prognostic value of urinary IL-18 are warranted.