Study to Learn When Platelets Return to Normal After One Loading Dose of Anti-platelet Drugs in Patients With Symptoms of Acute Coronary Syndromes

Recovery of Platelet Function After a Loading Dose of Prasugrel or Clopidogrel in Aspirin-Treated Subjects Presenting With Symptoms of Acute Coronary Syndromes

To investigate how platelets recover to normal function in subjects who have symptoms of a heart attack or unstable angina and who get a loading dose of prasugrel or clopidogrel for planned coronary angiography.

Inclusion Criteria:

• Men or women ≥18 to <80 years of age who present with any one of the following:
• symptoms of Acute Coronary Syndromes (ACS)
• clinical symptoms of angina, or a positive stress test or who return for routine follow up angiography post stent placement in whom co-administration of aspirin and a thienopyridine (that is, clopidogrel, ticlopidine, or prasugrel) is not contraindicated

Exclusion Criteria:

• Those presenting with ST-elevation MI (STEMI)
• histories of refractory ventricular arrhythmias
• an implanted defibrillator device
• congestive heart failure (NYHA Class III or above) within 6 months prior to screening
• significant hypertension
• subjects with a history or clinical suspicion of cerebral vascular malformations, transient ischaemic attack, or stroke
• bleeding disorders
• women known to be pregnant, who have given birth within the past 90 days, or who are breastfeeding