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 concurrenty 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

Inclusion Criteria:

• Patients presenting or admitted to hospital with symptoms suspected to represent an acute coronary syndrome.
• Able to randomize within 24 hours of the onset of the most recent episode of symptoms.
• At least one of the following additional criteria: (1) Troponin T of I or CK-MB above the upper limit of normal for the local institution and/or (2) ECG changes compatible with ischemia
• Written informed consent

Exclusion Criteria:

• Age < 21 years
• Any contraindication to low molecular weight heparin
• Hemorrhagic stroke within the last 12 months
• Indication for anticoagulation other than ACS.
• Pregnancy or women of childbearing potential who are not using an effective method of contraception
• Co-morbid condition with life expectancy less than 6 months
• Prior enrollment in one of the fondaparinux ACS trails or currently receiving an experimental pharmacologic agent