Neutrophil-to-lymphocyte ratio doesn’t predict short-term mortality, cardiac injury or left ventricular dysfunction after cardiac surgery

Abstract Introduction: The neutrophil-to-lymphocyte ratio (NLR) has been suggested as a potential biomarker for predicting adverse outcomes in various cardiovascular conditions. However, its utility in predicting short-term mortality, cardiac injury, or dysfunction following cardiac surgery remains unclear. This study aims to evaluate the relationship between NLR and these outcomes in patients undergoing cardiac surgery. Materials and Methods: A retrospective analysis was conducted on 75 patients who underwent cardiac surgery. The NLR was calculated pre- and postoperatively for each patient. NLR dynamics was calculated based on pre-and postop values. Outcomes of interest included in-hospital mortality, significant cardiac injury indicated by elevated creatine kinase-MB (CK-MB) levels, and significant new onset left ventricular dysfunction defined as a marked decrease in left ventricular ejection fraction (EF). Statistical analyses were performed to compare NLR valuse between patients who did and did not experience these adverse outcomes. Results: Data analysis showed no significant difference in the mean preop, postop and NLR dynamics between patients who died during hospitalization and those who survived. Similarly, the mean NLR did not significantly differ between patients with and without significant elevations in CK-MB levels or between those with stable versus decreased EF. No significant correlation was found between NLR values and studied outcomes. Conclusion: These findings suggest that the neutrophil-to-lymphocyte ratio is not a reliable predictor of short-term mortality, cardiac injury, or left ventricular dysfunction in patients following cardiac surgery. Further research should focus on identifying more effective biomarkers for these critical outcomes.