Drug sold to Sanofi-Aventis who sold it to GSK; OBS no longer owns study and does not have data.

The purpose of this research study is to obtain experience in the use of fondaparinux (Arixtra) as compared to heparin when administered to patients who undergo percutaneous coronary intervention (PCI). PCI is a mechanical procedure used to widen the narrowing in a coronary artery in patients with symptomatic coronary artery disease. Fondaparinux and heparin are drugs that inhibit blood clotting.

Inclusion criteria

• Scheduled for PCI, including PCI for non-ST elevation acute coronary syndromes (ACS), primary PCI for ST elevation myocardial infarction (MI) or elective PCI (with planned overnight stay in hospital). (Patients undergoing diagnostic heart catherization who are suitable candidates for "ad hoc" PCI are also eligible).

Exclusion criteria:

• Age < 21 years
• Activated Clotting Time (ACT) > 200 seconds immediately prior to PCI
• Use of low molecular weight heparin (LMWH) in the previous 6 hours before PCI
• Currently receiving an oral anticoagulant (OAC) agent with an INR > 1.8
• Thrombolytic therapy for ST elevation MI in the previous 24 hours before PCI
• Active internal bleeding or history of hemorrhagic diathesis
• Thrombocytopenia (platelet count < 100 x 10-9/L)
• Pregnant women or women of childbearing potential who are not using an effective method of contraception
• Known allergy to unfractionated heparin, fondaparinux, aspirin or clopidogrel
• Absolute contra-indication to anticoagulation
• Participation in other clinical research studies involving the evaluation of other investigational drugs or devices within 30 days of enrollment or prior participation in this study.