# Evaluation of the Cleveland Clinic Score for predicting acute kidney injury across different elective cardiac surgeries—a retrospective study

## TL;DR

This study evaluates how well the Cleveland Clinic Score predicts kidney injury after different heart surgeries, finding moderate accuracy overall but suggesting improvements for specific procedures.

## Contribution

The study validates the Cleveland Clinic Score's predictive ability for AKI across various cardiac surgeries and highlights the need for modifications in specific cases.

## Key findings

- The Cleveland Clinic Score showed moderate predictive ability for AKI (AUC 0.630) across all cardiac surgeries.
- The score was most accurate for coronary artery bypass grafting and aortic valve procedures.
- The score was particularly useful in predicting the need for renal replacement therapy.

## Abstract

Acute kidney injury (AKI) after cardiac surgery is a serious postoperative complication associated with an increased risk of mortality. The Cleveland Clinic Score (CCS) is one of the tools that allows preoperative assessment of the likelihood of developing AKI. However, the tool has not been validated in different types of cardiac surgery procedures. Our aim was to evaluate the CCS before different types of cardiac surgery and to assess the usefulness of this tool as a predictor of AKI.

In this retrospective study we included patients who underwent elective cardiac surgery in 2023. Our endpoint was AKI, as defined by the Kidney Diseases Improving Global Outcomes (KDIGO) criteria. The predictive value for AKI after cardiac surgery (CCS) was evaluated using receiver operating characteristic (ROC) curves and area under the curve (AUC) values.

A total of 610 patients underwent elective cardiac surgery. Patients with and without AKI were divided into CCS stages: stage I (57.8 vs 72.3%), stage II (36.1 vs 26.1%), stage III (5.4 vs 1.6%), stage IV (0.6 vs 0%). The AUC for all operations was 0.630 (95% CI [0.580–0.679], p < 0.001), stage I 0.428 (95% CI [0.376–0.480]; p = 0.006), stage II 0.550 (95% CI [0.498–0.602]; p = 0.057) and for stage III 0.519 (95% CI [0.467–0.572]; p = 0.464). The AUC values were significant only for coronary artery bypass grafting (CABG) 0.650 (95% CI [0.552–0.748]) and aortic valve replacement/plasty (AVR/AVP) 0.629 (95% CI [0.550–0.709]).

The overall CCS value showed a moderate predictive ability for AKI (AUC 0.630) and particularly useful for predicting renal replacement therapy (RRT), but for individual groups the scale should be modified by adding several new factors.