Different LD of Ticagrelor for Antiplatelet Effect in Patients With Non-ST-segment Elevation ACS Undergoing PCI

After providing written informed consent, all patients will be randomized to receive ticagrelor 360mg or 180mg loading dose(LD),then 90mg bid maintenance dose starting 12 hours after LD.PCI will performed in 2h-72h after they are given the loading dose.All patients should receive acetylsalicylic acid (ASA) 75 to 100 mg daily unless intolerant.IPA at 0, 0.5, 1, 2, 8, 24h after the loading dose of ticagrelor will be measured. CK-MB, troponin I, myoglobin, CRP will be detected at 0h, before PCI, 8h after PCI, 24h after PCI. ECG will be conducted at 0h and within 24h after PCI. Patients returned 28 days for follow-up visits after the loading dose of ticagrelor, documented any adverse events.

Inclusion criteria

• Provision of informed consent prior to any study specific procedures.
• Male or non-pregnant female; aged from 18 to 80 years old.
• Patients with non-ST-segment elevation acute coronary syndromes who were scheduled to undergoing PCI.

Exclusion criteria

• Any contraindication against the use of ticagrelor.
• On treatment with a P2Y12 receptor antagonist in past 30 days.
• Known allergies to aspirin or ticagrelor.
• On treatment with oral anticoagulant (Vitamin K antagonists, dabigatran, rivaroxaban).
• Known blood dyscrasia or bleeding diathesis.
• ST-segment elevation acute myocardial infarction.
• Non-ST segment elevation acute coronary syndrome with high-risk features warranting emergency coronary angiography.
• Left ventricular ejection fraction ≤30%; renal failure with creatinine 3 mg/dl; history of liver disease; an increased risk of bradycardia, and concomitant therapy with drugs interfering with CYP3A4 metabolism.