von Willebrand factor disruption and continuous-flow circulatory devices

Area of Science:

• Cardiovascular Science
• Hematology
• Biomedical Engineering

Background:

• Bleeding is a major complication of continuous-flow left ventricular assist devices (VADs).
• von Willebrand factor (VWF) is crucial for hemostasis, mediating platelet adhesion and aggregation.
• Acquired von Willebrand disease (AVWD) is implicated in VAD-associated bleeding due to shear-induced VWF defects.

Purpose of the Study:

• To review the pathobiology of von Willebrand factor (VWF) disruption in patients with VADs.
• To discuss the role of acquired von Willebrand disease (AVWD) in VAD bleeding.
• To outline current diagnostic and management strategies for AVWD in the context of VADs.

Main Methods:

• Review of clinical and experimental data on VWF function and VAD complications.
• Analysis of the mechanism of shear-induced VWF unfolding and proteolysis by ADAMTS13.
• Synthesis of information on diagnostic approaches and therapeutic interventions for AVWD.

Main Results:

• Pathologic shear stress in VADs causes VWF unfolding and degradation of large VWF multimers.
• This process, mediated by ADAMTS13, leads to qualitative VWF defects characteristic of AVWD.
• These VWF abnormalities contribute significantly to the bleeding diathesis observed in VAD patients.

Conclusions:

• Acquired von Willebrand disease is a key factor in bleeding complications associated with continuous-flow VADs.
• Understanding the pathobiology of VWF disruption is essential for managing VAD-related bleeding.
• Effective diagnostic and management strategies are needed to mitigate bleeding risks in VAD recipients.