Effect of Prasugrel on Platelets After One Week in Patients Already Taking Clopidogrel After a Cardiac Event

A Pharmacodynamic Comparison of Prasugrel (LY640315) Versus Clopidogrel in Subjects With Acute Coronary Syndrome Who Are Receiving Clopidogrel

This study will compare the effect of a prasugrel 10-mg maintenance dose with a clopidogrel 75-mg maintenance dose on platelet activity, approximately 1 week after the first dose of study drug, in subjects who have been taking clopidogrel 75 mg daily following a percutaneous coronary intervention (PCI) with placement of a stent, performed to treat acute coronary syndrome (ACS).

Inclusion Criteria:

• Present with a recent history of an ACS event based on the disease diagnostic criteria between 30 and 330 days prior to enrollment, and who state that they are supposed to be taking daily aspirin and maintenance dose 75-mg clopidogrel.
• Are of a legal age (and at least 18 years of age but less than 75 years of age) and competent mental condition to provide written informed consent before entering the study.

Exclusion Criteria:

• Left main coronary artery stent or left anterior descending (LAD) bifurcation stent.
• Have any form of coronary revascularization (percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) planned to occur during the study (from signing consent through the final visit).
• Have undergone CABG or PCI within 30 days of entry into the study.
• Receiving or will receive oral anticoagulation or other antiplatelet therapy (other than aspirin and clopidogrel) that cannot be safely discontinued for the duration of the study.
• Receiving daily treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) that cannot be discontinued or are anticipated to require daily treatment with NSAIDs during the study.
• Have any of the following: history of ischemic or hemorrhagic stroke intracranial neoplasm, arteriovenous malformation, or aneurysm history of transient ischemic attack (TIA), have a body weight less than 60 kilograms (kg).