Elevated serum cystatin C level is an independent predictor of contrast-induced nephropathy and adverse outcomes in patients with peripheral artery disease undergoing endovascular therapy

Objective: The aim of this study was to investigate the association of serum cystatin C levels with contrast-induced nephropathy (CIN) and adverse clinical events in patients with peripheral artery disease (PAD). Methods: A total of 240 PAD patients who received endovascular therapy were included in this retrospective analysis. Serial serum levels of creatinine and cystatin C before and within 48 hours of endovascular therapy were evaluated for the incidence of CIN. The relationship between serum cystatin C levels and the incidence of major adverse events, defined as a composite of all-cause death, myocardial infarction, stroke, amputation, and target vessel revascularization, was investigated. Results The incidence of CIN increased from 1.7% to 27.9%, depending on the quartile of baseline cystatin C level. Baseline serum cystatin C level (area under the curve of the receiver operating characteristic curve, 0.757; 95% confidence interval [CI], 0.696-0.735) predicted the incidence of CIN better than baseline serum creatinine level (area under the curve, 0.629; 95% CI, 0.563-0.691; P <.001). An elevated baseline cystatin C level was an independent predictor of CIN (hazard ratio, 14.37; 95% CI, 4.11-50.19; P <.001) and major adverse events in patients with PAD (hazard ratio, 2.57; 95% CI, 1.28-5.17; P =.008). Conclusions We found elevated baseline cystatin C level to be an independent risk factor for CIN and a predictor of all-cause mortality and major adverse events in patients with PAD undergoing endovascular therapy.