Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting
Abstract
Background: An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing surgical revascularization. Methods: Baseline clinical details were obtained prospectively in 1938 patients undergoing CABG. The differential leukocyte was measured before surgery, and patients were followed-up 3.6 years later. The primary end point was all-cause mortality. Results: The preoperative N/L ratio was a powerful univariable predictor of mortality (hazard ratio [HR] 1.13 per unit, P < .001). In a backward conditional model, including all study variables, it remained a strong predictor (HR 1.09 per unit, P = .004). In a further model, including the European system for cardiac operative risk evaluation, the N/L ratio remained an independent predictor (HR 1.08 per unit, P = .008). Likewise, it was an independent predictor of cardiovascular mortality and predicted death in the subgroup of patients with a normal white blood cell count. This excess hazard was concentrated in patients with an N/L ratio in the upper quartile (>3.36). Conclusion: An elevated N/L ratio is associated with a poorer survival after CABG. This prognostic utility is independent of other recognized risk factors.
Citation
Gibson, P.H, Croal, B.L., Cuthbertson, B.H, Small, G.R., Ifezulike, A.I., Gibson, G., Buchan, K.G., El-Shafei, H., and Hillis, G.S. (2007). Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting. American Heart Journal [Online], 154(5), pp.995-1002. Available from: http://www.sciencedirect.com/science/journal/00028703 [Accessed 10 April 2008]