Platelet-to-lymphocyte ratio is a predictor of long-term mortality in patients with acute coronary syndrome

Introduction: Atherosclerosis is a chronic inflammatory process and inflammation is an important component of acute coronary syndrome (ACS). Platelet-to-lymphocyte ratio (PLR) is a useful parameter showing the degree of the inflammatory response. Aim: To explore the association between PLR and long-term mortality in patients with ACS. Material and methods: A total of 538 patients who had a diagnosis of ACS between January 2012 and August 2013 were followed up to 60 months. On admission, blood sampling to calculate PLR and detailed clinical data were obtained. Results: In total, 538 patients with a mean age of 61.5 +/- 13.1 years (69% male) were enrolled in the study. Median follow-up was 79 months (IQR: 74-83 months). Patients were divided into 3 tertiles based on PLR levels. Five-year mortality of the patients was significantly higher among patients in the upper PLR fertile when compared with the lower and middle PLR tertile groups (55 (30.7%) vs. 27 (15.0%) and 34 (19.0%); p < 0.001, p = 0.010 respectively). In the Cox regression analysis, a high level of PLR was an independent predictor of 5-year mortality (OR = 1.005, 95% CI: 1.001-1.008, p = 0.004). Kaplan-Meier analysis according to the long-term mortality-free survival revealed the higher occurrence of mortality in the third PLR tertile group compared to the first (p < 0.001) and second tertiles (p = 0.009). Conclusions: PLR, which is an easily calculated and universally available marker, may be useful in long-term risk classification of patients presenting with ACS.