Risk Score for Predicting AKI from Contrast-Enhanced CT (Pre-CT AKI score): Training and Validation from Retrospective Cohort.

Background: The lack of a recognized risk evaluation for Contrast-associated acute kidney injury (CA-AKI) after contrast-enhanced computed tomography (CECT) makes it challenging to counsel patients before the procedure. This study aims to identify the incidence of CA-AKI post CECT, assess the associated risk factors, develop and validate a predictive score.

Methods: All adult patients who underwent CECT in 2018 to 2022 were included in the training cohort while those in 2023 formed the external validation cohort. Exclusions applied to patients with CKD stage 5, recent dialysis, or incomplete data. Multiple logistic regression was employed to identify risk factors. The area under the receiver operating characteristic curve (AUROC) was used to evaluate both internal and external validation.

Results: From 21,878 enrolled patients, 6,042 and 2,463 met the inclusion criteria for the training and validation cohorts with a mean eGFR of 86.0 (26.4) and 81.4 (27.6) mL/min/1.73 m2, respectively. In the training cohort, 492 patients (8.1%) developed CA-AKI, and 49 (0.8%) required dialysis. Independent risk factors for CA-AKI included male gender, clinical setting, hemoglobin levels of <10 g/dL, and baseline eGFR less than 90 mL/min/1.73 m2. The model, using a weighted integer score derived from these factors, exhibited an AUROC of 0.715 (95% CI: 0.692-0.743) in the training cohort and 0.706 (95% CI: 0.663-0.748) in the validation cohort.

Conclusions: CECT can lead to CA-AKI in specific populations. The Pre-CT AKI risk score for CA-AKI following CECT demonstrated good discriminative power and can be easily applied in clinical practice.