Efficacy of ticagrelor compared to clopidogrel in improving endothelial function in patients with coronary artery disease: a systematic review

Background Ticagrelor and clopidogrel are antiplatelet drugs that act by binding to the adenosine diphosphate P2Y12 receptor. Previous studies have compared between them regarding the endothelial function effect. Objectives This systematic review aims to summarize the evidence comparing the efficacy of ticagrelor vs. clopidogrel in improving endothelial function in patients with coronary artery disease (CAD). Methods In August 2021, the Scopus, PubMed, Web of Science, and Cochrane library were searched systematically for eligible trials. We included randomized controlled trials that compared the efficacy of ticagrelor vs. clopidogrel in improving endothelial function in patients with CAD. Results Seven trials (n = 511) were included in our systematic review. Ticagrelor resulted in a greater elevation of the level of progenitor cells CD34+ KDR+ and CD34+ 133+ (P = 0.036 and P = 0.019, respectively), with a lower rate of endothelial cell apoptosis rate (P < 0.001). Moreover, ticagrelor showed superiority regarding nitric oxide, radical oxygen species, and soluble P-selectin levels (P = 0.03, P = 0.02, and P = 0.019, respectively). Flow-mediated dilation findings differed between the studies (P = 0.004 vs. P = 0.39). Conclusion Ticagrelor appears to exert an additional improvement in endothelial function compared with clopidogrel in patients with coronary heart disease.