- Known clinical site of bleeding or predisposition to bleeding (e.g., GI bleed, hematuria, hemorrhagic CVA,retroperitoneal hematoma, diabetic retinopathy, hemorrhagic pericardial effusion, or hemorrhagic pleural effusion. Patients who have a known clinical site of bleeding may be enrolled if the investigator deems the risk of continued thrombosis to outweigh the potential bleeding risk.