• Test the hypothesis that CS-747 plus aspirin is superior to clopidogrel plus aspirin in the treatment of subjects with acute coronary syndrome who are to undergo percutaneous coronary intervention (PCI),
• as measured by a reduction in the composite endpoint of cardiovascular (CV) death,nonfatal myocardial infarction (MI), or nonfatal stroke at a median follow-up of at least 12 months

The sponsors of this investigational drug are developing prasugrel as a possible treatment for patients with acute coronary syndrome (heart attack or chest pain) who need, or are expected to need, a percutaneous coronary intervention (PCI; also called a balloon angioplasty). Prasugrel will be compared with clopidogrel to determine which drug is better at reducing deaths, future heart attacks, or stroke.

• Coronary Arteriosclerosis
• Acute Coronary Syndrome

• Drug: Prasugrel
• Drug: Clopidogrel

• Pride YB, Wiviott SD, Buros JL, Zorkun C, Tariq MU, Antman EM, Braunwald E, Gibson CM; TIMI Study Group. Effect of prasugrel versus clopidogrel on outcomes among patients with acute coronary syndrome undergoing percutaneous coronary intervention without stent implantation: a TRial to assess Improvement in Therapeutic Outcomes by optimizing platelet inhibitioN with prasugrel (TRITON)-Thrombolysis in Myocardial Infarction (TIMI) 38 substudy. Am Heart J. 2009 Sep;158(3):e21-6.
• Montalescot G, Wiviott SD, Braunwald E, Murphy SA, Gibson CM, McCabe CH, Antman EM; TRITON-TIMI 38 investigators. Prasugrel compared with clopidogrel in patients undergoing percutaneous coronary intervention for ST-elevation myocardial infarction (TRITON-TIMI 38): double-blind, randomised controlled trial. Lancet. 2009 Feb 28;373(9665):723-31.
• Mega JL, Close SL, Wiviott SD, Shen L, Hockett RD, Brandt JT, Walker JR, Antman EM, Macias W, Braunwald E, Sabatine MS. Cytochrome p-450 polymorphisms and response to clopidogrel. N Engl J Med. 2009 Jan 22;360(4):354-62. Epub 2008 Dec 22.
• Wiviott SD, Braunwald E, Angiolillo DJ, Meisel S, Dalby AJ, Verheugt FW, Goodman SG, Corbalan R, Purdy DA, Murphy SA, McCabe CH, Antman EM; TRITON-TIMI 38 Investigators. Greater clinical benefit of more intensive oral antiplatelet therapy with prasugrel in patients with diabetes mellitus in the trial to assess improvement in therapeutic outcomes by optimizing platelet inhibition with prasugrel-Thrombolysis in Myocardial Infarction 38. Circulation. 2008 Oct 14;118(16):1626-36. Epub 2008 Aug 31.
• Antman EM, Wiviott SD, Murphy SA, Voitk J, Hasin Y, Widimsky P, Chandna H, Macias W, McCabe CH, Braunwald E. Early and late benefits of prasugrel in patients with acute coronary syndromes undergoing percutaneous coronary intervention: a TRITON-TIMI 38 (TRial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet InhibitioN with Prasugrel-Thrombolysis In Myocardial Infarction) analysis. J Am Coll Cardiol. 2008 May 27;51(21):2028-33.
• Wiviott SD, Braunwald E, McCabe CH, Horvath I, Keltai M, Herrman JP, Van de Werf F, Downey WE, Scirica BM, Murphy SA, Antman EM; TRITON-TIMI 38 Investigators. Intensive oral antiplatelet therapy for reduction of ischaemic events including stent thrombosis in patients with acute coronary syndromes treated with percutaneous coronary intervention and stenting in the TRITON-TIMI 38 trial: a subanalysis of a randomised trial. Lancet. 2008 Apr 19;371(9621):1353-63. Epub 2008 Apr 2.
• Wiviott SD, Braunwald E, McCabe CH, Montalescot G, Ruzyllo W, Gottlieb S, Neumann FJ, Ardissino D, De Servi S, Murphy SA, Riesmeyer J, Weerakkody G, Gibson CM, Antman EM; TRITON-TIMI 38 Investigators. Prasugrel versus clopidogrel in patients with acute coronary syndromes. N Engl J Med. 2007 Nov 15;357(20):2001-15. Epub 2007 Nov 4.

Inclusion Criteria:

• A person who has been diagnosed with acute coronary syndrome and is to undergo a percutaneous intervention.
• A person who is of the legal age of 18 and is mentally competent to provide a signed written informed consent.
• If a woman is of childbearing potential (i.e., before menopause), she must test negative for pregnancy and agree to use a reliable method of birth control.

Exclusion Criteria:

• A person who has had a stroke within the last 3 months.
• A person who has active internal bleeding or has a history of a bleeding disorder.
• Individuals who are at an increased risk of bleeding based on laboratory criteria evaluated by the treatment physician.
• A person who has liver disease; for example, cirrhosis.
• A person who has a condition such as alcoholism, mental illness, or is drug dependent.