Acquired Hemophilia A in a Patient Undergoing Aortic Valve Replacement with Warfarin Anticoagulation Therapy

Hematol Transfus Int J 2017, 4(2): 00078 those using the anti-coagulant agent, warfarin [4,5]. One case of a patient undergoing coronary artery bypass grafting was noted among 7cases of surgery-associated acquired hemophilia [2]. A 66-year-old man underwent aortic valve replacement for severe aortic valve stenosis. After surgery, he was administered warfarin (2mg/day) for anticoagulation and the international normalized ratio (INR) was controlled between 1.8 and 2.0. Approximately 5 months later, he suddenly presented with severe subcutaneous hematoma in the extremities without trauma. Clotting activities worsened (INR, 2.81; activated partial thromboplastin time [aPTT], 103 seconds; normal range, 24-39 seconds). Although warfarin was stopped and the INR normalized (INR 1.07), the aPTT remained prolonged (aPTT, 88.9 seconds). Other anticoagulants such as heparin sodium and dabigatran were not used. Lupus anticoagulant test (dilute Russel viper venom time) was negative. Therefore, we measured the factor VIII (F VIII) clotting activity and its inhibitor’s activity; based on this, the patient was diagnosed with acquired hemophilia A for bleeding tendency (F VIII activity, 1.2%; F VIII inhibitor, 152 Bethesda units [BU]). From the definite diagnosis, prednisolone (1mg/kg) was started. However, active bleeding from the upper gastrointestinal tract suddenly occurred. Massive blood transfusion was given until use of recombinant factor VII therapy. Prior to recombinant factor VII infusion, we administered red cell concentrate (RCC) (26 units) and fresh frozen plasma (FFP) (12 units). Two units of RCC (280ml) or 2 units of FFP (120ml) were derived from 400 ml of donated whole blood in Japan. After recombinant factor VII infusion, RCC (6units) alone was transfused. Factor VIII inhibitor activity lowered (<0.5BU) and bleeding tendency resolved. Prednisolone was tapered gradually and then completely discontinued. Fortunately, relapse of acquired hemophilia A was not noted even without prednisolone (aPTT, 26.7-36.0s). Re-administration of warfarin induced good control of the patient’s anticoagulation (INR, 1.82.0) and no relapse of acquired hemophilia A has been seen.