Contraindications to anticoagulation include: subarachnoid hemorrhage, intracranial hemorrhage, hemorrhagic cerebral infarction, active gastrointestinal bleeding, active ulcer disease, active tuberculosis, severe active bleeding, malignant hypertension, recent (within 7-10 days) brain, eye, or spinal surgery. In addition, patients with a recent history of stroke, recent major surgery, severe trauma, hypertension, liver failure, kidney failure, cardiac insufficiency, hemangioma, severe infection, drug allergy.