Cyc-C is superior to creatinine in the early diagnosis of contrast-induced nephropathy

Background: Contrast-Induced Nephropathy (CIN) is associated with prolonged hospitalization and serial measurements of creatinine should be monitored in all patients at risk. Because of the delayed increase in creatinine, CIN may be overlooked. The aim of this study is to assess whether changes in Cystatin C (CyC) after 48 hours from contrast media exposure is a reliable indicator of acute kidney injury and the validity of a risk scoring tool for CyC based CIN. Methods: We enrolled 121 patients for whom coronary angiography were planned. The risk score for CIN was calculated and serum creatinine and CyC were measured before and 48 hours after coronary angiography. CyC and creatinine based CIN was calculated as a 25% increase from baseline within 48 hours from contrast media exposue. Results: Mean serum CyC and creatinine concentrations were found to be 0.88±0.27 mg/dL and 0.79±0.22 mg/dL, respectively before the procedure and 1.07±0.47 mg/dL and 0.89±0.36 mg/dL, respectively 48 hours after contrast media exposure (p<0.001). CyC based CIN occured in 44 patients (36.36%) and sCr based CIN occured in 20 patients (16.52%) after the procedure. Mean risk score was found to be 4.00±3.478 and 3.60±4.122 for CyC based CIN and sCr based CIN, respectively and found to be significantly increased in CyC based CIN group (p<0.001) (Table 1). Table 1. Mean Risk Scores in CyC based and sCr based CIN groups Conclusions: CyC measurement 48 hours after contrast media exposure is superior to serum creatinine measurement for the diagnosis of CIN and Mehran risk scoring tool is in good correlation with CyC increase for the prediction of CIN.