Postoperative infection-related mortality and lymphocyte-to-C-reactive protein ratio in patients undergoing on-pump cardiac surgery: a novel predictor of mortality?

Objective: This study aims to investigate the relationship between postoperative infection-related mortality and lymphocyte-to-C-reactive protein ratio (LCR), a newly defined parameter with the combination of inflammatory and immune parameters, in patients undergoing cardiac surgery.

Patients And Methods: Between January 2016 and November 2021, 236 patients who underwent on-pomp cardiac surgery with median sternotomy and developed postoperative infection were analyzed retrospectively. Patients were divided into six groups according to the types of postoperative infection. Preoperative, perioperative, and postoperative variables of the patient groups were compared, and factors affecting postoperative mortality were evaluated.

Results: The mortality rate in the patient group we included in the study was 22.9%. Mortality rates did not differ significantly between the infection groups. However, when the LCR value was evaluated between the groups, there was a statistically significant difference (p<0.001). The preoperative LCR cut-off value, which predicts postoperative infection-related mortality, was determined as 133.46 (area under the curve (AUC): 0.607, p=0.017, 48.1% sensitivity, and 47.8% specificity). In the multivariate analysis, postoperative cerebrovascular event (OR: 78.365, 95% CI: 12.367-496.547, p<0.001) and Intensive Care Unit (ICU) stay (odds ratio (OR): 1.136, 95% confidence interval (CI): 1.004-1.284, p=0.042) variables were found to be independent predictive factors of postoperative infection-related mortality in the model. There was no positive differentiation of the type of infection in predicting mortality.

Conclusions: The calculated LCR value is a novel and remarkable parameter in estimating postoperative infection-related mortality in patients undergoing cardiac surgery.