OBJECTIVE: To probe into the effects of antiplatelet drugs therapy guided by platelet aggregation rate on the short-term and long-term prognosis in patients with acute coronary syndrome（ ACS） after percutaneous coronary intervention（ PCI）. METHODS: Totally 92 patients with ACS undergoing PCI admitted into Tangshan Union Medical College Hospital from Jan. 2018 to Aug. 2019 were selected and randomly divided into guidance group and conventional group

with 46 cases in each group. Patients in the guidance group were given antiplatelet drugs such as clopidogrel under the guidance of platelet aggregation rate after surgery

while patients in the conventional group were given conventional doses of antiplatelet drugs

both groups were treated for 1 year. Changes in thromboelastogram indicators [coagulation reaction time（ R）

clotting time（ K） and maximum thrombus amplitude（ MA） ]

platelet parameters [platelet count（ PLT）

mean platelet volume（ MPV）

thrombocytocrit（ PCT） and platelet distribution width（ PDW） ] were observed before（ T0）

1 month（ T1） and 12 months（ T2） after treatment

and the major adverse cardiovascular events（ MACE） and bleeding complications at T1 and T2 were recorded. RESULTS: Compared with that at T0

the R and K were significantly longer and MA was significantly lower in both groups at T1 and T2; the R and K were significantly longer and MA was significantly lower in the guidance group than in the conventional group at T1

with statistically significant differences（ P <0. 05）. Compared with that at T0

the PLT

MPV

PCT and PDW of both groups were significantly lower at T1 and T2; the PLT

MPV

PCT and PDW were significantly lower in the guidance group than in the conventional group at T1

with statistically significant differences（ P < 0. 05）. The incidence of MACE of the guidance group was significantly lower than that of the conventional group at T1

with statistically significant difference（ P < 0. 05）

while the difference in incidence of MACE between two groups at T2 was not statistically significant（ P > 0. 05）. The difference in incidence of bleeding at T1 and T2 between two groups were not statistically significant（ P > 0. 05）. CONCLUSIONS: The application of antiplatelet drug therapy guided by platelet aggregation rate can significantly reduce the incidence of recent MACE after PCI in patients with ACS

without increasing bleeding time

but has no significant effect on long-term prognosis.