Acquired von Willebrand syndrome caused by paravalvular prosthetic mitral regurgitation

The patient is an 83-year-old man who developed dyspnoea. He underwent aortic valve replacement at the age of 37 followed by mitral valve replacement 32 years after initial intervention (Panel A). He repeated gastrointestinal bleeding every 2–3 months and developed severe anaemia in the range of haemoglobin level 5–7 g/dL, requiring repeated blood transfusions and endoscopic argon plasma coagulation to angiodysplasia in the stomach (Panel B). The coexistence of repeated gastrointestinal bleeding suggested a Hyede’s syndrome-like condition despite no organic aortic valve stenosis in this case,1 while blood tests suggested mechanical haemolysis due to the prosthetic valve. von Willebrand factor (VWF) multimer analysis showed a loss of large multimers (Panel D). Detailed observation of transoesophageal echocardiography revealed paravalvular regurgitation only in the mitral valve prosthesis (Panel A). The patient underwent re-mitral valve replacement surgery. The normalization of macromolecular multimers was confirmed in the examination on the seventh postoperative day (Panel E) followed by healing angiodysplasia (Panel C). Acquired von Willebrand syndrome (AvWS) is a rare disorder caused by quantitative/qualitative abnormalities of VWF due to various aetiologies.2 In the present case, the possible process of developing AvWS is that high shear stress at the site of physical stenosis on paravalvular regurgitation resulted in a loss of VWF large multimers, leading to angiodysplasia of the stomach followed by repeated gastrointestinal bleeding.3 When anaemia both due to repeat gastrointestinal bleeding and haemolysis occurs in patients with prosthetic valves, the possibility of AvWS should be included in the differential diagnosis.