Abstract 18936: Kidney Injury Molecule-1 (KIM-1) is a Promising Urinary Biomarker to Detect Cardiorenal Syndrome in Children with Dilated Cardiomyopathy (DCM)

Abstract

Background: Type II cardiorenal syndrome (CRS) describes renal dysfunction in the presence of chronic heart dysfunction. Novel urinary acute kidney injury biomarkers (NUB) have not been studied in children with DCM. We aim to 1) Evaluate the correlation between four NUB and severity of LV dysfunction, and 2) Determine the best marker to detect CRS in children with DCM. Methods: We are conducting a cross-sectional study in children with DCM and LV dysfunction. Enrolled children had an echocardiogram to measure the LV ejection fraction (EF). Urine samples were collected at the same visit to measure the NUB: KIM-1, NGAL, IL-18, and L-FABP. NUB levels were adjusted for each mg of urinary creatinine. Glomerular filtration rate was estimated using modified Schwartz formula (eGFR) when Creatinine level (Cr) is available. Univariate analysis was conducted between patients (pts) with EF< 45% and EF ≥ 45%. ROC analysis was performed for all NUB and GFR. 2x2 tables were constructed from NUB cutoffs to maximize specificity for EF <45%. Results: 30 pts (14.2 ±6.4 years old) have been enrolled to date. 13 (43%) had EF<45%. Although all NUB levels were higher in pts with EF <45%, only KIM-1 was significantly higher [836.5 (±844.1) vs. 442.8 (±249.5) pg/mg cr , P one-tailed =0.04]. Area under the curve for KIM-1 was 0.61 to predict EF <45%, compared to 0.53 for eGFR. A KIM-1 cutoff of 900 pg/mg cr yielded highest correct EF classification (38% sensitivity, 94% specificity). 6/30 (20%) pts had KIM-1 >900; 5/6 (83%) had EF of <45% vs. 8/24 (33%) with KIM-1<900 (P one-tailed =0.03). Conclusions: Our pilot data suggest DCM pts with EF<45% tend to have higher NUB urinary levels indicating worse CRS than pts with EF≥45%. Urinary KIM-1 may be the most predictive test to detect CRS compared to other NUB and eGFR. We anticipate confirming this finding by increasing the study’s power.