Correlation of Preoperative Neutrophil Lymphocyte Ratio with EuroSCORE as a Predictor of In-Hospital Mortality Following an Isolated Coronary Artery Bypass Graft: A 7-year Retrospective Study

Background Patients undergoing coronary artery bypass graft (CABG) are risk stratified preoperatively by computing the EuroSCORE. Studies have shown that neutrophil-to-lymphocyte ratio (NLR) is a specific predictor of increased cardiovascular risk. This study aimed to determine the correlation between NLR and EuroSCORE and postoperative in-hospital mortality following isolated CABG. Methods This was a seven -year retrospective chart review that included patients who underwent isolated elective or urgent CABG. The patients’ EuroSCORE was computed based on patient records. Correlation was assessed using Pearson’s correlation test and receiver operating characteristics (ROC) curve analysis was used to determine the optimum cut-off level of preoperative NLR to predict mortality. Results Out of the 103 included patients, only seven died (all following urgent CABG). Compared to survivors, those who died had a higher proportion of diabetes mellitus (DM) (p=0.030), a lower clearance (p=0.024), a higher EuroScore (p<0.001) and a higher NLR (p<0.001). Logistic multivariate analysis showed that only the presence of DM was associated with mortality. A threshold NLR value of 4.7 was able to predict mortality (AUC= 1.0, sensitivity: 43%, specificity: 100%). Conclusion NLR is a practical, clinically acceptable biomarker linked to predicting mortality following an isolated CABG. Keywords Neutrophil-to-lymphocyte ratio, EuroSCORE, mortality, CABG.