Why people with LVADs bleed: the role of von Willebrand factor and blood-vessel changes

Von Willebrand Factor Hyperactivity, Angiogenesis and LVAD-Induced Bleeding

NIH-funded research University of Texas Hlth Sci Ctr Houston · NIH-11320841

Researchers will compare blood and vessel changes in people with left ventricular assist devices (LVADs) to find how a clotting protein called von Willebrand factor (VWF) and high blood flow forces lead to bleeding.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionUniversity of Texas Hlth Sci Ctr Houston NIH-funded
Lab location1 site (Houston, United States)
Project IDNIH-11320841 on NIH RePORTER

What this research studies

If you join, doctors will collect blood from people before and after LVAD implantation and from healthy volunteers to look at the size and activity of VWF proteins. Lab tests and bioassays will measure how high blood-flow (shear) conditions change VWF and how readily it is cut by the enzyme ADAMTS13. The team will also look for small abnormal blood vessels (angiodysplasia) that can bleed and use computational tools to link lab findings to real bleeding events. Together these steps aim to pinpoint why only some patients with lost VWF multimers actually experience serious bleeding.

Who could benefit from this research

Good fit: People with an implanted LVAD or those about to receive an LVAD—especially if they've had unexplained bleeding—are the most likely candidates to participate.

Not a fit: Patients without an LVAD or whose bleeding is caused by unrelated conditions (for example, an inherited bleeding disorder or known medication effects) may not directly benefit from this work.

Why it matters

Potential benefit: Could lead to tests that identify LVAD patients at high risk of bleeding and to new ways to prevent or treat device-related bleeding.

How similar studies have performed: Previous studies have documented loss of large VWF multimers in nearly all LVAD patients, but the exact shear-driven mechanisms and why only some patients bleed remain unresolved, so this work builds on known findings but addresses key unanswered questions.

Where this research is happening

Houston, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Conditions Acquired Von Willebrand syndromeAcquired von Willebrand disease
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.