Relationship Between Platelet to Lymphocyte Ratio and Stable Coronary Artery Disease: Meta-Analysis of Observational Studies.

Recent studies have reported a relationship between the platelet to lymphocyte ratio (PLR) and acute coronary syndromes. The aim of the present study was to investigate the association between PLR and stable coronary artery disease (CAD). A systematic search was conducted based on electronic databases (Cochrane, PubMed, Elsevier, Medline, and Embase). A total of 14 studies (n = 4,871) were included in the meta-analysis. Compared with the non-CAD group, PLR was significantly higher in CAD group (P = .002). After further classification according to the Gensini score, the cases with atherosclerosis demonstrated a higher PLR than those without atherosclerosis (P < .001). Platelet to lymphocyte ratio was higher in the severe atherosclerosis group compared with the mild atherosclerosis group (P < .001). Compared with the poor coronary collateral circulation (CCC) group, PLR was significantly lower in the good CCC group (P < .001). The PLR was significantly higher in patients with coronary slow flow (CSF) than those with normal coronary flow (P = .01). On the basis of current evidence, an elevated PLR was associated with stable CAD, and it might be useful for predicting CAD severe stenosis, collateral circulation, and CSF. Future studies are needed to clarify the relationship between PLR and stable CAD.