Abstract 19133: Von Willebrand Factor Inhibition Improves Endothelial Function In Patients With Stable Angina
Von Willebrand factor (vWF) is a marker of endothelial dysfunction. Improvement of endothelial function with aggressive medical therapy is associated with significant reduction in vWF levels. ALX-0081 (Ablynx, Belgium) is a novel nano-antibody directly inhibiting vWF. Purpose: To investigate whether direct inhibition of vWF by ALX-0081 is associated with improvement in endothelial function.
Methods: Fifty-five stable angina patients (pts) with single vessel disease undergoing percutaneous coronary intervention (PCI) were randomized either to ALX-0081 treatment (n=38, dose-range 2–9 mg) or placebo (n=17) given at the time of PCI. Endothelial function (endoscore) by endothelial peripheral arterial tonometry (Endopat, ITAMAR) and vWF activity by ristocetin test (vWF:RiCo) were assessed before PCI (BL), 6 hours and 24 hours after PCI. Vasoactive medications were withheld 24 hours before the procedure. All pts were on chronic aspirin and clopidogrel.
Results: PCI was uneventful in all pts. Full inhibition of vWF activity (vWF:RiCo<20%) was achieved in all treated pts within one hour from ALX-81 administration. In placebo pts, no significant changes were observed in Endoscore at 6 and 24 hours. Endoscore significantly increased in treated pts at 6 (p=0.03 vs. BL) and 24-hours (p=0.01 vs. BL).
Conclusions: A direct inhibition of vWF with ALX-0081 nanobody is associated with a significant improvement in peripheral endothelial function.
- © 2010 by American Heart Association, Inc.