Midkine as an Early Biomarker of Contrast-induced Acute Kidney Injury in Chronic Kidney Disease Patients Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome: A Single-center Prospective Study

Background: Contrast-induced acute kidney injury (CI-AKI), is an important complication of percutaneous coronary intervention (PCI). We aimed to study the role of serum midkine (MK) as an early biomarker of CI-AKI. Methods: We conducted a prospective observational cohort study. It includes 100 chronic kidney disease (CKD) patients with an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m2. All patients were undergoing PCI for ACS. We measured serum midkine before, 2 and 24 hours after PCI.  Results: The mean age of the patients was 70.32±3.62 years, 74% males. Twenty-seven patients developed CI-AKI. The CI-AKI group has a history of diabetes mellitus (DM) and/or dyslipidemia, history of diuretics, metformin and/or angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (ACEI/ARBs) use. The CI-AKI patients have low left ventricular ejection fraction (LVEF) (EF < 45%) and low Creatinine Clearance (CrCl) before PCI. The CI-AKI received more contrast volume, had a longer duration of PCI  and had high Mehran risk score after PCI. Comparison between the two studied groups regarding serum MK showed that there was a statistically significant difference regarding serum MK 2 hours after PCI. Receiver operating characteristic (ROC) curve analysis for serum MK showed that serum MK measured 2 hours after PCI was statistically significant to predict CI-AKI. Conclusion: An early Serum MK after PCI can be used as an early predictor of CI-AKI in ACS patients.