Preservation of high-molecular-weight von Willebrand factor multimers in severe aortic stenosis: A 4-year follow-up from pregnancy through aortic valve replacement: A case report

In stenotic conditions, such as aortic valve stenosis (AS), elevated shear stress resulting from pressure gradients can lead to the loss of high-molecular-weight von Willebrand factor multimers (HMWM), which are crucial for hemostasis. This loss may result in hemorrhagic complications. We present a case study examining HMWM levels in a patient experiencing increased pressure gradients owing to two distinct mechanisms. A 34-year-old primigravida with AS (mean pressure gradient, 20 mmHg) was followed from the pregnancy period through aortic valve replacement four years later. During cesarean delivery, despite an acute increase in the peak pressure gradient (90–100 mmHg) due to pregnancy-related elevated blood volume and cardiac output, HMWM levels remained preserved. Furthermore, HMWM levels were maintained even four years later when the pressure gradient increased due to progressive valve stenosis. Pregnancy-enhanced coagulation and sustained compensatory mechanisms protected against HMWM degradation despite severe AS. These adaptive responses suggest individual protective factors against hemostatic complications that warrant further investigation.