The merits of the prognostic nutritional index and neutrophil-to-lymphocyte ratio in predicting outcomes of coronary artery bypass grafting: a retrospective cohort study

BACKGROUND: Coronary artery bypass grafting (CABG) carries a risk for serious adverse events. The Prognostic Nutritional Index (PNI) and Neutrophil-to-Lymphocyte Ratio (NLR), are simple measures of nutritional and inflammatory statuses, have been proposed as a potential predictor of postoperative outcomes. This study aimed to assess the predictive performance of preoperative PNI and NLR and their dynamic changes for post-CABG outcomes. METHODS AND MATERIALS: The study investigated the medical records of 327 patients who underwent CABG between February 20, 2020, and February 19, 2025. RESULTS: The overall complication and mortality rates were 15%, and 3.36% respectively. The preoperative PNI decreased significantly (P1 < 0.001) at 24-h postoperative and at the time of discharge. At the time of discharge, the mean PNI value increased significantly (P2 < 0.001) compared to that determined at 24-h postoperative. The magnitude of ∆PNI at discharge was significantly smaller than that at 24-h postoperatively (P3 < 0.001). Multivariate binary logistic regression identified preoperative PNI as an independent predictor of 1-month mortality, while ΔPNI at 24 h was independently associated with 1-month mortality. CONCLUSION AND RECOMMENDATIONS: PNI is a simple and inexpensive marker that may serve as a potential predictor of short-term outcomes after CABG. Lower preoperative PNI and greater early postoperative PNI decline were associated with adverse short-term outcomes after CABG, whereas preoperative NLR did not retain independent significance after multivariable adjustment; however, further prospective multicenter studies are required to confirm these findings.