[A hemostatic disorder caused by high shear stress: acquired von Willebrand syndrome]

The von Willebrand factors (VWFs) play critical role in hemostasis and thrombosis formation. VWFs are produced in and secreted as large multimers from endothelial cells, and shear stress-dependently cleaved into 2-80 multimers by their specific protease, ADATS13. Because high molecular weight VWFs play important roles in platelet aggregation, the loss of high molecular weight VWFs caused by pathological high-shear stress induces a hemostatic disorder known as acquired von Willebrand syndrome (AVWS) type IIA. The most well-known cause of this loss is aortic stenosis, which is accompanied by gastrointestinal bleeding most often as a result of angiodysplasia; this comprises a condition known as Heyde's syndrome. Additionally, various cardiovascular diseases that generate excessive high-shear stress in the blood stream, such as hypertrophic obstructive cardiomyopathy (HOCM), mitral regurgitation, pulmonary hypertension, and some congenital heart diseases, and mechanical circulatory support systems, such as left ventricular assist device (LVAD), cause AVWS.