Background: Kidney injury molecule-1 (KIM-1) is a novel biomarker that was initially identified and evaluated in patients with acute kidney injury. It predominantly indicates tubular injury and is an earlier and more sensitive indicator of acute kidney injury than plasma creatinine. Objective: To evaluate the role of KIM-1 as an early marker of renal dysfunction in children with heart failure and to assess whether KIM-1 concentration is related to heart failure severity and cardiac function. Patients and Methods: This case-control study was carried out at the Cardiology Unit, Outpatient Cardiology Clinic, and Clinical Pathology Unit, Zagazig University Hospitals during the period from November 2018 to May 2019 included 93 children. Results: KIM-1 was higher in patients
with acute and chronic heart failure as compared with controls also it has positive correlations with LVEDD, LVESD, and serum creatinine, while it had a negative correlation with GFR. An optimal admission KIM-1 cut off at >588 ng/ml, with a sensitivity of 85.5%, a specificity of 83.9% for WRF prediction in HF, with an area under the curve (AUC= 0.948, P>0.001). While the sensitivity of GFR and serum creatinine was 67.7%, 72.6% respectively and the specificity was 71%, 90.3% respectively with an area under the curve of 0.773 and 0.875 respectively. Conclusions: KIM-1 can be considered as a sensitive diagnostic marker superior to both GFR and creatinine for early detection of impaired renal function in acute and chronic HF even before GFR is markedly reduced and even before serum creatinine is significantly affected.