Abstract: Objective　To explore the effect of ticagrelor on platelet function (PF) in patients with minor acute stroke or transient ischemic attack (TIA). Methods　A total of 81 minor acute stroke or TIA patients were randomly divided into the experimental group (39 patients) and the control group (42 patients). The experimental group was treated with ticagrelor combined with aspirin after admission, and changed to ticagrelor alone after 21 days. The control group was treated with clopidogrel after clopidogrel and aspirin treating for 21 days. On admission, day 7 and day 90 Sonoclot assay was used to measure PF in the two groups. Results　(1) Compared with the control group, the values of activated clotting time (ACT) and time to peak (PT) increased on the 7th day of treatment in the experimental group, and PF decreased. ACT also increased 90 days after treatment (P＜0.05). There were no significant differences in clot rate (CR) and maximal clot signal (MCS) before and after treatment in the two groups (P＞0.05). (2) Compared with those at admission, the values of ACT and TP increased and the PF and MCS decreased in the two groups (P＜0.05). (3) There were no significant differences in the main adverse events between the two groups (P＞0.05). Conclusion　Compared with clopidogrel, ticagrelor can inhibit platelet function more rapidly in patients with minor acute stroke or TIA, but does not increase major bleeding events.

Key words: stroke, ischemic attack, transient, platelet function tests, blood coagulation tests, platelet count, ticagrelor, clopidogrel, Sonoclot