Association between C-reactive protein-to-platelet ratio and acute kidney injury in cardiac arrest survivors

The C-reactive protein-to-platelet ratio (CPR) is a composite marker reflecting the interplay between inflammation and coagulation. This study aimed to investigate the association between CPR and the development of acute kidney injury (AKI) in postcardiac arrest (CA) patients.

We conducted a secondary analysis of previously published data from a cohort of cardiac arrest survivors admitted to the ICU. We employed univariate and multivariate logistic regression models, restricted cubic spline analysis, and subgroup analysis to elucidate the relationship between CPR and AKI. Receiver operating characteristic (ROC) curve analysis and decision curve analysis were performed to describe the discriminative ability and net benefit of Ln-CPR for AKI in an exploratory manner.

A total of 309 patients were analyzed, of whom 163 (52.8%) developed CA-AKI. Multivariable analysis revealed that each 1-unit increase in Ln-CPR (log-transformed) was associated with 1.53 times the odds of CA-AKI (OR: 1.53, 95% CI: 1.24-1.90). Additionally, in the fully adjusted model, the highest Ln-CPR level was associated with higher odds of AKI compared to the lowest level (OR: 3.93, 95% CI: 1.78-8.68). Restricted cubic spline analysis demonstrated a linear association between Ln-CPR and the development of CA-AKI. The area under the ROC curve for Ln-CPR was 0.629 (95% CI: 0.567-0.690, p < 0.001). Exploratory decision curve analysis suggested only a marginal net benefit within a limited threshold probability range.

Elevated CPR was independently associated with an increased risk of AKI in ICU-admitted cardiac arrest survivors.