To construct a risk prediction model for contrast-associated acute kidney injury(CA-AKI) in elderly patients with lower extremity arteriosclerosis obliterans(ASO) after interventional surgery and to perform internal validation.

A total of 685 elderly patients with ASO who underwent interventional treatment in a tertiary grade A hospital in Zhejiang province from January 2022 to December 2024 were selected as the study subjects.According to a 7∶3 ratio between the modeling group and the validation group,479 patients were included in the modeling group and 206 patients were included in the validation group.Logistic regression analysis was used to identify influencing factors for CA-AKI occurrence in elderly patients with ASO after interventional surgery.A risk prediction model was constructed. The clinical validity of the model was evaluated using the area under the receiver operating characteristic curve(AUC),Hosmer-Lemeshow test,calibration curve,and decision curve analysis(DCA).

The incidence of CA-AKI was 5.43% in the modeling group and 4.85% in the validation group. Logistic regression analysis showed that acute lower limb ischemia,serum albumin and estimated glomerular filtration rate were independent influencing factors for CA-AKI occurrence(P<0.05).The AUC of the constructed prediction model was 0.84(95%CI 0.76-0.91),with a sensitivity of 68.0%,specificity of 87.0%,and a maximum Youden index of 0.550.The Hosmer-Lemeshow test results showed χ²=9.602(P=0.294).The calibration curve demonstrated good agreement between predicted risk and actual risk.The DCA curve indicated that the prediction model could achieve net benefit within the clinically relevant threshold probability range.The AUC for internal validation was 0.79(95%CI 0.68-0.90),with a sensitivity of 45.5% and specificity of 87.7%.

The risk prediction model for CA-AKI occurrence in elderly patients with ASO after interventional surgery has good predictive performance and could provide a reference for early clinical identification of high-risk populations for CA-AKI in elderly patients with ASO after interventional surgery.