Hexadecasaccharide (SR123781A) in Patients With Unstable Angina or Non-ST-Segment Elevation Myocardial Infarction

Inclusion Criteria: * A person with a diagnosis of acute coronary syndrome who is scheduled to undergo a PCI within 48 hours. * A person who is of the legal age of 21, who is mentally competent, and who has signed a written informed consent Exclusion Criteria: * A person with known allergy or any contra-indication to active control. * A person who has received heparin during more than 48 hours before inclusion in the study. * A person treated with warfarin (oral anticoagulant). * A person with current bleeding or recognized increased risk of bleeding or history of intracranial hemorrhage. * A person who has had a stroke within the last 6 months. * A person with uncontrolled hypertension despite antihypertensive therapy. * A person with history of clinically significant reduction in blood platelets or neutrophils (white blood cells). * A person who has laboratory evidence of significantly reduced renal function or who is dependent on renal dialysis. * A person who has a coronary bypass performed during the previous month. * A pregnant or nursing woman or a woman of childbearing potential (before menopause) who does not have a negative pregnancy test and does not use a reliable method of birth control. * A person who has received any investigational treatment in the preceding month.