Background: Contrast-induced acute kidney injury (CI-AKI), specifically after percutaneous coronary intervention (PCI) constitutes a highly challenging health concern. Thus, prediction of patients at risk is paramount for early detection and prevention. A novel and promising biomarker, Dickkopf3 (DKK-3), has been investigated for its role in prediction of CI-AKI. Yet, its role in prediction of CI-AKI after PCI is not well recognized. Therefore, this study aimed to assess the predictive value of pre-contrast urinary DKK-3/urinary creatinine (Ur DDK-3/Ur Cr) for post-PCI-CI-AKI.

Methods: This prospective cohort study included 150 patients who underwent PCI, for them serum creatinine, urinary creatinine, estimated glomerular filtration rate (eGFR), 24-hour urinary protein, urinary DKK-3 level, and Ur DDK-3/Ur Cr were measured pre-contrast, then repeated 48 hours post-contrast.

Results: CI-AKI was diagnosed in 14% of patients after PCI, and their pre-contrast Ur DKK-3 and Ur DKK-3/Ur Cr were significantly higher than patients without CI-AKI (p˂0.001). Pre-contrast eGFR, serum and urinary creatinine did not show significant difference in both groups. Significant predictors of CI-AKI included diabetes mellitus, age, BMI, pre-contrast HbA1C%, random blood sugar, eGFR, platelets count, proteinuria, and Ur DKK-3. Importantly; pre-contrast Ur DKK-3/Ur Cr had the highest odds ratio (OR 6) for predicting CI-AKI. At a cut off value of 18.5 pg/mg, Ur DKK-3/Ur Cr has 87.5% sensitivity and 64% specificity for predicting post-PCI CI-AKI (p˂0.001).

Conclusions: Increased pre-contrast Ur DDK-3/Ur Cr may independently predict patients at risk of developing post-PCI-CI-AKI.