n.The patient is receiving therapeutic anticoagulation with warfarin, low-molecular weight heparin or similar agents. Patients receiving prophylactic, low-dose anticoagulation therapy are eligible provided that the coagulation parameters defined in the inclusion criteria (INR ≤ 1.5 and aPTT ≤ 1.5 x ULN) or (PT ≤ 1.5 x ULN and aPTT ≤1.5 x ULN) are met.