The predictive value of elevated neutrophil to lymphocyte ratio for long-term cardiovascular mortality in peripheral arterial occlusive disease

Background: Peripheral arterial occlusive disease (PAOD), which is common in male gender and elderly population, is related with increased cardiovascular mortality and morbidity. Neutrophil to lymphocyte ratio (NLR) has been found to be an independent predictor of cardiovascular mortality in atherosclerosis. The aim of the present study was to investigate the association between NLR and cardiovascular mortality both in patients with intermittent claudication and critical limb ischemia. Methods: In a retrospective study, 593 consecutive patients who had been admitted to the inpatient ward of the vascular department of a large tertiary training and research hospital with diagnosis of symptomatic PAOD between May 2009 and September 2012 were included. Patients were divided into two groups according to their NLR as follows: high NLR (NLR > 3.0) and low NLR (NLR <= 3.0) groups. Results: During the course of the present study [median follow-up period of 20 months (interquartile range, 12-27)], 75 deaths occurred out of 508 patients (14.8%). Cardiovascular mortality was found to be significantly higher in elevated NLR group (n = 43) as compared to low NLR group (n = 32) (23.6% vs 9.8%, respectively; p < 0.001). Even after adjustment of various risk factors, NLR > 3 and age were found as independent predictors of long-term cardiovascular mortality in Cox regression analysis [hazard ratios (95% confidence interval), 2.04 (1.26-3.30) and 1.04 (1.01-1.07), p = 0.004 and p = 0.004, respectively]. Conclusion: We demonstrated that an increased NLR was related with higher cardiovascular mortality in patients with PAOD, who were admitted with critical limb ischemia or intermittent claudication. NLR, which reflects the patient's inflammatory status, is an inexpensive and readily available biomarker that provides an additional level of risk stratification beyond that provided by conventional risk scores in predicting long-term cardiovascular mortality in PAOD. (C) 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.