- Patients will be excluded if they have: i) a contra-indication for clopidogrel or prasugrel or ticagrelor (as per monograph), ii) have an intolerance to aspirin, iii) have absolute requirement for ticagrelor or prasugrel (e.g. stent thrombosis, allergic reaction to clopidogrel), iv) requirement for anti-coagulation treatment, v) a history of stroke, TIA or intracranial hemorrhage , vi) a platelet count < 100,000/μl, vii) a known bleeding diathesis, viii) hematocrit <30% or >52%, ix) severe liver dysfunction, x) renal insufficiency (creatinine clearance < 30ml/min), xi) adjuvant therapy with a glycoprotein IIbIIIa inhibitor.