Role of serum cystatin C in the prediction of contrast-induced nephropathy after intra-arterial interventions

BACKGROUND: The diagnosis of contrast-induced nephropathy (CIN) is usually based on changes in serum creatinine (sCr). However, sCr has poor sensitivity as a biomarker of kidney injury. The aim of this study was to investigate the usefulness of serum cystatin C (sCysC) to predict CIN after intra-arterial interventions. METHODS: A total of 360 consecutive patients underwent intra-arterial procedures using digital subtraction angiography. SCr, sCysC, and estimated glomerular filtration rate were measured at 1 to 2 days before and at 48, 72 h, and 7 days after the procedure. RESULTS: Thirty-one patients (8.61%) developed CIN. Receiver operating characteristic (ROC) curve analysis showed that pre-operative sCysC levels had good discriminatory power (area under the curve [AUC] = 0.634; 95% confidence interval [CI] = 0.526–0.743) for evaluating the risk of CIN after an endovascular procedure, with a sensitivity of 53.33% and specificity of 73.70%. ROC analysis showed that sCysC at 48 h after contrast medium administration was predictive of CIN after an endovascular procedure (AUC = 0.735; 95% CI = 0.647–0.822) with satisfactory sensitivity of 74.20% and specificity of 63.90%. Diabetes mellitus was an independent risk factor for CIN (odds ratio = 2.778; 95% CI = 1.045–7.382; P = 0.040). CONCLUSIONS: SCysC is an appropriate biomarker to predict the occurrence of CIN. Baseline sCysC before an intervention is useful to obtain a preliminary estimate of the risk of CIN. A 48-h cut-off value of sCysC of 0.99 mg/L after an endovascular procedure may help to rule out patients at lower risk of CIN.