Application of 17 Contrast-Induced Acute Kidney Injury Risk Prediction Models

Contrast-induced acute kidney injury (CI-AKI) is a frequent complication of percutaneous coronary interventions (PCI). Various groups have developed and validated risk scores for CI-AKI. Although the majority of these risk scores achieve an adequate accuracy, their usability in clinical practice is limited and greatly debated.

With the present study, we aimed to prospectively assess the diagnostic performance of recently published CI-AKI risk scores (up to 2018) in a cohort of patients undergoing PCI.

We enrolled 1,247 consecutive patients (80% men, mean age 62 ± 10 years) treated with elective or urgent PCI. For each patient, we calculated the individual CI-AKI risk score based on 17 different risk models. CI-AKI was defined as an increase of ≥25% (liberal) or ≥0.5 mg/dL (strict) in pre-PCI serum creatinine 48 h after PCI.

CI-AKI definition and, therefore, CI-AKI incidence have a significant impact on risk model performance (median negative predictive value increased from 85 to 99%; median c-statistic increased from 0.516 to 0.603 using more strict definition criteria). All of the 17 published models were characterized by a weak-to-moderate discriminating ability mainly based on the identification of "true-negative" cases (median positive predictive value 19% with liberal criterion and 3% with strict criterion). In none of the models, c-statistic was >0.800 with either CI-AKI definition. Novel, different combinations of the >35 independent variables used in the published models either by down- or by up-scaling did not result in significant improvement in predictive performance.

The predictive ability of all models was similar and only modest, derived mainly by identifying true-negative cases. A new approach is probably needed by adding novel markers or periprocedural characteristics.