Why people with LVADs bleed: the role of von Willebrand factor and blood-vessel changes
Official title: Von Willebrand Factor Hyperactivity, Angiogenesis and LVAD-Induced Bleeding
Funded at University of Texas Hlth Sci Ctr Houston · NIH-11320841 · Data updated 2026-11-12
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 type | R01 grant |
|---|---|
| Study type | NIH-funded research |
| Funding institution | University of Texas Hlth Sci Ctr Houston NIH-funded |
| Lab location | 1 site (Houston, United States) |
| Project start | April 10, 2023 |
| Project end | March 31, 2028 |
| Funding year | 2026 |
| Award (this year) | $594,080 |
| NIH project number | 5R01HL163549-04 |
| Project ID | NIH-11320841 on NIH RePORTER |
Who could benefit from this research
✓Could help
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.
✕Less likely to help
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.
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.
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 gone: 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
-
University of Texas Hlth Sci Ctr Houston
Houston, United States Active
Researchers
- Principal investigator: Nascimbene, Angelo — University of Texas Hlth Sci Ctr Houston
- Study coordinator: Nascimbene, Angelo
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About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page.