The Role of CRP/Albumin Ratio in Predicting the Risk of Postoperative Acute Renal Failure in Patients Undergoing Coronary Bypass Surgery

Background: The evolution of acute kidney injury (AKI) following coronary artery bypass grafting (CABG) operations may have several immediate effects on the health of the patients. Whether the preoperative C-reactive protein (CRP)/albumin ratio is a biomarker that can be used to predict the development of AKI after CABG is still under investigation. This study examined the ability of the CRP/albumin ratio to predict the risk of postoperative AKI. Methods: This study was a retrospective analysis of 186 patients who underwent CABG surgery at the Eskisehir City Hospital. Patients were categorized into low and high-risk groups based on preoperative CRP/albumin ratios. The diagnosis of AKI was based on an increase in serum creatinine level or oliguria according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Preoperative CRP and albumin values, demographic characteristics, postoperative creatinine, estimated glomerular filtration rate (eGFR) and length of hospitalization were evaluated. Results: In patients who developed AKI, their CRP/albumin ratio was 2.48 (1.24–4.48), vs non-AKI patients; 1.21 (0.53–2.34); p < 0.001. The CRP/albumin area under the Receiver Operating Characteristic (ROC) curve (AUC) ratio in ciR was 0.782 with an AUC of 74.2% sensitivity and 71.8% specificity at a threshold value of 1.85. Patients who developed AKI also had a mean Intensive Care Unit (ICU) stay of 5 (3–8) days and a mean length of stay of 12 (9–18) days, which was longer than the control group, regardless of the cause of the hospitalization; (p < 0.001). Conclusion: High CRP/albumin ratio is an important risk marker for the development of AKI after CABG. Assessing the preoperative CRP/albumin ratio could be beneficial in predicting the risk of AKI and in devising appropriate postoperative management protocols for these patients.