Prognostic Value of Platelet-Lymphocyte and Neutrophil-Lymphocyte Ratios in Predicting Acute Kidney Injury After Coronary Artery Bypass Surgery

Background Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) surgery is a major complication and seriously affects both mortality and disease process. In this study, we investigated the predictive value of platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR), biomarkers of inflammation, on the development of AKI. Methods We retrospectively evaluated 96 patients who underwent CABG surgery between January 2020 and December 2023. Patients were divided into two groups according to the development of postoperative acute kidney injury (AKI): AKI (n = 32) and non-AKI (n = 64). Preoperative and postoperative platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) values were analyzed and compared between the groups. The diagnosis of AKI was based on changes in serum creatinine level according to KDIGO 2012 criteria. Results In the group that developed AKI, preoperative PLR and NLR values were significantly higher (145.8 ± 62.3 and 3.8 ± 1.9, respectively; p < 0.05). In the early postoperative period, this difference became even more significant (PLR: 278.5 ± 95.6, NLR: 12.6 ± 5.3; p < 0.001). According to ROC analysis, the area under the curve (AUC) value of PLR's capacity to predict AKI was calculated as 0.728 and the cut-off value was determined as 132.5. For NLR, the AUC value was 0.692 and the cut-off value was 3.2. Conclusions PLR and NLR have emerged as important biomarkers in predicting the development of acute kidney injury (AKI) after CABG surgery. In particular, high preoperative PLR values may be an independent risk factor for the risk of AKI. These findings may be a valuable guide in clinical practice for early detection and timely intervention of patients at risk of AKI.