Prognostic Value of Serum Cystatin C for Predicting Contrast-Induced Nephropathy in Elderly Individuals Aged Over 80 Years.

OBJECTIVE: To explore the predictive value of serum cystatin C (CysC) for contrast-induced acute kidney injury (CI-AKI) in elderly individuals. METHODS: The study included 102 elderly patients (80 years) who underwent percutaneous coronary interventions at the Fourth People's Hospital of Shanghai Affiliated to Tongji University between September 2020 and January 2024. Based on their diagnosis, they were divided into those with CI-AKI (n = 10) and those without CI-AKI (n = 92). A fully automated biochemical analyzer was used to measure the serum CysC levels at baseline and 48 h after coronary angiography or percutaneous coronary intervention in the two groups, and the association of serum CysC levels and other relevant clinical indicators with the occurrence of CI-AKI was evaluated to determine the predictive value of baseline serum CysC for diagnosing contrast agent-induced nephropathy based on receiver operating characteristic curves. RESULTS: Age, serum CysC, and serum creatinine levels were significantly higher in the CI-AKI group than in the non-CI-AKI group. Serum CysC was found to be a predictor of CI-AKI based on an area under the curve of 0.731 (95% confidence interval = 0.569-0.893). CONCLUSION: The occurrence of contrast-induced nephropathy is related to age, serum CysC, and serum creatinine levels. In particular, serum CysC had high predictive value for CI-AKI in those aged above 80 years.