Neutrophil/lymphocyte ratio as a mortality predictor following coronary artery bypass graft surgery

Background: In this study, we aimed to investigate the newly introduced inflammatory biomarker, neutrophil/ lymphocyte ratio, as a mortality predictor following coronary artery bypass graft (CABG) surgery. Methods: Between December 2011 and April 2012, 210 consecutive patients who underwent isolated CABG surgery in our clinic were prospectively analyzed. The baseline characteristics of the patients and preoperative neutrophil/ lymphocyte ratio were determined. The postoperative follow-up was 86.1±38.9 days. The primary endpoint was all-cause mortality. Results: Eight patients (3.8%) died of whom four deaths occurred during the first 30 days of follow-up. Univariate analyses revealed a significant difference in the preoperative neutrophil/lymphocyte ratio between the groups in which mortality was seen and the group in which no mortality was observed (p=0.037). The Receiver operating characteristic (ROC) curve showed a threshold value of 2.81 for neutrophil/lymphocyte ratio (AUC=0.72, sensitivity: 75%, specificity: 67%). Logistic regression analysis of the variables with significant differences between two groups revealed that the neutrophil/lymphocyte ratio over its threshold value was an independent predictor for mortality (OR 6.47, 95% CI 1.18-35.38, p=0.031). Conclusion: Neutrophil/lymphocyte ratio, which can be easily calculated, can be used as an independent factor in predicting early mortality following CABG surgery.