The dual antiplatelet therapy of aspirin combined with ticagrelor is the preferred antiplatelet therapy for patients with ST segment elevation myocardial infarction (STEMI) who receive primary percutaneous coronary intervention (PPCI). Compared with clopidogrel, ticagrelor can inhibit platelets faster and more effectively, and improve prognosis. However, there is still a lack of research on the application of reduced dose ticagrelor in STEMI patients receiving PPCI treatment.

To compare the different doses of ticagrelor on the efficacy and safety in patients with STEMI based on propensity score matching (PSM) .

The patients with STEMI who underwent PPCI and antiplatelet therapy with ticagrelor at the Fifth Department of Cardiology, Second Hospital of Hebei Medical University from June 2019 to May 2021 were selected consecutively. According to the different maintenance doses of ticagrelor, patients were divided into a reduced dose group (n=60) and a standard group (n=180), using ticagrelor 60 mg/time (2 times/day) and 90 mg/time (2 times/day), respectively. The PSM method was used to perform a 1∶1 match between two groups, with matching variables including gender, age, medical history, Killip grade at admission, and intervention related parameters. Finally, 54 patients were included in the each group. Follow-up was conducted on both groups at 1 month, 3 months, and 6 months after discharge, and platelet parameters as well as clinical events were recorded and compared between the two groups of patients.

There was no statistically significant difference in baseline data, intervention parameters, and incidence of major adverse cardiovascular events (MACEs) during hospitalization between the two groups of patients after PSM (P>0.05). At baseline, there was no statistically significant difference in platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW) between the two groups (P>0.05). The level of platelet aggregation rate (PAR) of patients in the reduced dose group was lower than that of the standard group (P<0.05). At discharge, the MPV of patients in the reduced dose group was higher than that in the standard group, and the PDW was lower than that in the standard group (P<0.05). At one month after discharge, there was no statistically significant difference in PLT, MPV, PDW, and PAR between the two groups (P>0.05). At 3 months after discharge, the PDW of patients in the reduced dose group was higher than that of the standard group (P<0.05). At 6 months after discharge, the MPV of patients in the reduced dose group was higher than that of the standard group (P<0.05). There was no statistically significant difference in PLT and PAR before and after discharge between patients in the reduced dose group and those in the standard group (P>0.05). Patients in the reduced dose group and standard group had higher MPV than baseline at discharge, lower PDW than baseline at discharge in the reducde dose group, and lower PAR than baseline at discharge in the standard group (P<0.05). The MPV of patients in the reduced dose group at 1, 3, and 6 months after discharge was lower than those at discharge, and the PDW was higher than that at discharge (P<0.05). The PAR of the standard group patients at 1, 3, and 6 months was lower than baseline and higher than that at discharge (P<0.05). There was no statistically significant difference in the incidence of MACEs and severe bleeding events between the two groups during follow-up (P>0.05) .

Reduced dose of ticagrelor treatment is safe and effective for STEMI patients undergoing PPCI.