An International, Randomized, Double-blind Study Evaluating the Efficacy and Safety of Fondaparinux Versus Enoxaparin in the Acute Treatment of Unstable Angina/Non ST-segment Elevation MI Acute Coronary Syndromes

Study Objectives PRIMARY OBJECTIVE: To evaluate whether fondaparinux is at least as effective as or superior to enoxaparin in preventing death, myocardial infarction or refactory ischemia up to Day 9 in the acute treatment of patients with unstable angina/non ST-segment elevation myocardial infarction concurrently managed with standard medical therapy. SECONDARY OBJECTIVE: If non inferiority of fondaparinux is established on initial statistical analysis in a second step, superiority of fondaparinux to enoxaparin will be evaluated statistically. - To determine whether fondaparinux is superior to enoxaparin in reducing death or MI at Day 9 - To determine whether fondaparinux is superior to enoxaparin in reducing major bleeding events up to Day 9 - To determine whether the relative effect on the primary end point of fondaparinux versus enoxaparin is sustained at Day 14, Day 30, Day 90 and Day 180 Study Drug: Patients will be randomized to receive either: - Fondaparinux 2.5 mg once and placebo-enoxaparin twice daily by subcutaneous injection or - Enoxaparin (1mg/kg) twice and fondaparinux-placebo once daily by subcutaneous injection Duration of Therapy: - Fondaparinux 2.5mg daily for 8 days or hospital discharge (whichever is earlier) - Enoxaparin 1mg/kg b.i.d. x 2-8 days or until clinically stable. - Patients should receive an ASA and all other standard medical therapies. Substudy: - A substudy comparing routine early coronary angiography immediately or as soon as possible (but no later than 24 hours after randomization) and intervention versus delayed (>48 hrs) coronary angiography and intervention. Primary Outcome: The first occurence of any component of the following composite up to Day 9: - Death - Myocardial Infarction - Refractory Ischemia