Comparison of Systemic Inflammation Indices With Post-Cardiac Surgery Mortality and Morbidity

Background: The neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), and lymphocyte–monocyte ratio (LMR) are recognized markers linked to inflammation and have been studied across various fields. This study aimed to evaluate which systemic inflammation indices are more specific to post-cardiac surgery mortality and morbidity. Method: A total of 1528 cardiac surgery patients were retrospectively analyzed, including a subset of 1205 patients who underwent coronary artery bypass grafting (CABG). This study assessed the associations between the NLR, PLR, and LMR and postoperative complications. The predictive accuracy of indices was also specifically compared within the CABG subgroup. While the NLR and PLR indicated the occurrence of events, the LMR, with a receiver operating characteristic curve below 0.5, was interpreted as “free of events”. The cut-off values were determined as NLR: 3.10, PLR: 143.9, and LMR: 3.52. Results: The NLR correlated with higher mortality and complications, whereas the PLR showed no significant relation to neurological complications. The LMR was found to be related to the non-occurrence of events. Patients with higher NLR and PLR values experienced increased mortality and major adverse cardiac and cerebrovascular events, as well as a higher incidence of complications, including postoperative revision, atrial fibrillation (AF), and renal issues. Conversely, higher LMR values corresponded with lower rates of such complications. Conclusion: The NLR has emerged as a crucial indicator for predicting mortality and complications in cardiac surgery patients, more so than the PLR and LMR. Specifically, the NLR can be used to indicate the risk of mortality and complications in cardiac surgery. This prediction can be supported further using the PLR and LMR.