 - Patients not receiving therapeutic anticoagulation must have an INR 1,5 ULN and aPTT 1,5 ULN within 7 days prior to randomization. The use of full dose anticoagulants is allowed as long as the INR or aPTT is within therapeutic limits according to the medical standard in the institution and the patient has been on a stable dose for anticoagulants for at least two weeks at the time of randomisation. 