# Risk factors for acute kidney injury after coronary artery bypass graft surgery: a systematic review and meta-analysis

## TL;DR

This study identifies key risk factors for kidney damage after heart surgery, which can help doctors better predict and manage complications.

## Contribution

A systematic review and meta-analysis consolidating evidence on risk factors for AKI after CABG surgery.

## Key findings

- Older age, diabetes, and prolonged cardiopulmonary bypass are significant risk factors for AKI after CABG.
- Intra-aortic balloon pump use and red blood cell transfusion are strongly associated with AKI occurrence.
- The study confirms the importance of cardiopulmonary bypass duration as a major contributor to AKI.

## Abstract

Acute kidney injury (AKI) is one of the common and severe complications following coronary artery bypass graft (CABG) surgery, significantly increasing patient mortality, complication rates, and length of hospital stay. Although numerous studies have explored risk factors for postoperative AKI after CABG, results remain inconsistent. This systematic review and meta-analysis aim to synthesize existing evidence to identify the primary risk factors for AKI following CABG.

Systematically searched PubMed, Embase, Web of Science, and Cochrane Library databases from their inception to 20 September 2025. Observational studies reporting risk factors for postoperative AKI following CABG were included. Two researchers independently performed literature screening, data extraction, and quality assessment. Random-effects models were used to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). The I2 statistic was employed for heterogeneity analysis, and funnel plots and Egger’s test were used to assess publication bias.

A total of 17 research papers involving 33,809 patients were included. The results of the meta-analysis suggest that older age [OR = 1.05, 95% CI (1.03, 1.08)], prolonged cardiopulmonary bypass [OR = 1.14, 95% CI (1.06, 1.22)], diabetes [OR = 1.29, 95% CI (1.15, 1.45)], intra-aortic balloon pump [OR = 3.19, 95% CI (1.74, 5.85)], transfusion of red blood cells [OR = 1.73, 95% CI (1.25, 2.38)] may be associated with the occurrence of AKI after CABG.

Meta-analysis results indicate that older age, prolonged cardiopulmonary bypass duration, diabetes, intra-aortic balloon pump use, and red blood cell transfusion are all significant risk factors for AKI following CABG. Among these, prolonged cardiopulmonary bypass duration and intra-aortic balloon pump use exert a particularly pronounced effect on AKI occurrence.

[https://www.crd.york.ac.uk/prospero/], identifier [CRD420251144655].