Different antiplatelet drugs played various role in coronary artery disease. The mechanisms were unclear. Platelet reactivation maybe was one of major causes. Compared with clopidogrel, Ticagrelor is more powerful antiplatelet drug. However, because of increased bleeding and dyspnea risk, both loading double dose and following second dose time had potential risk and inconvenient in routine clinical work, especially in elective PCI of comparable stable patients in Chinese. The benefit and risk should be balanced in such patients. The investigators supposed loading single dose and followed by second routine time dose was superior to clopidogrel and safer than ticagrelor previously prescribed.

All admission patients were divided into two groups, the first group were prescribed loading dose (180 mg) ticagrelor, the second group were prescribed with 90 mg ticagrelor. We measured both platelet activity and platelet reactivity using the LTA at baseline, pre-operation and post-operation. All bleeding or dyspnea events were recorded in hospital period.

Primary endpoints: platelet activity, platelet reactivity using the LTA and safety events were recorded in hospital period.

Inclusion Criteria:

coronary artery disease, percutaneous coronary intervention

Exclusion Criteria:

high risk bleeding patient, allergic to the drugs

Chinese