The purpose of this study is to show that, when compared with heparin (enoxaparin or unfractionated heparin) and routine GPIIb/IIIa inhibition (either started upfront or at the time of percutaneous coronary intervention [PCI]; Arm A):

1. Bivalirudin with routine GPIIb/IIIa inhibition (either started upfront or at the time of PCI; Arm B) provides non-inferior or superior overall clinical outcomes and
2. Bivalirudin alone (Arm C) reduces clinically significant bleeding. An important secondary objective for this comparison is to show that bivalirudin is not inferior for ischemic complications.