title: The prognostic value of the platelet-to-lymphocyte ratio in acute coronary syndrome: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The aim of this study was to investigate whether the platelet-to-lymphocyte ratio (PLR) is an independent predictor of all-cause mortality and cardiovascular (CV) events in patients with acute coronary syndrome (ACS).
  
  
  METHODS
  PubMed, Embase, and the Cochrane Library were searched for relevant cohort studies regarding the association between PLR and outcomes of patients with ACS. Either a random- or a fixed-effect model was used for pooling data.
  
  
  RESULTS
  Eight studies involving 6627 patients with ACS were included. The cut-off PLR value for defining risk groups was 150, and patients were assigned to the low (≤ 150) or high (> 150) PLR groups. The pooled relative risk (RR) values of in-hospital and long-term mortality were 2.15 (95% CI [confidence interval] 1.73-2.67; p < 0.00001) and 2.27 (95% CI 1.35-3.80; p = 0.002), respectively, comparing the high and the low PLR groups. Compared with the low PLR group, the high PLR group had a significantly increased risk of in-hospital (RR 1.95; 95% CI 1.30-2.91; p = 0.001) and long-term (RR 1.50; 95% CI 1.08-2.09; p = 0.01) major adverse CV events.
  
  
  CONCLUSIONS
  Elevated PLR was found to be a predictor of all-cause mortality and CV events.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Cardiology, Fifth Affiliated Hospital of Xinjiang Medical University, Urumqi, China, China. hsx0016@163.com.
authors.forename: Suxia
authors.initials: S
authors.lastname: Han
authors.forename: Liansuo
authors.initials: L
authors.lastname: Zhou
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000401:mortality; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011379:Prognosis; D012306:Risk
keywords: acute coronary syndrome; all-cause mortality; major adverse cardiovascular events; meta-analysis; platelet-to-lymphocyte ratio