- Patients on full-dose anticoagulants must be on a stable dose of warfarin and have an in-range international normalized ratio (INR) (usually between 2 and 3) or be on a stable dose of low molecular weight (LMW) heparin; patients receiving anti-platelet agents are also eligible; in addition, patients who are on daily prophylactic aspirin or anticoagulation for atrial fibrillation are eligible