Profile of von Willebrand factor antigen and von Willebrand factor propeptide in an overall TIA and ischaemic stroke population and amongst subtypes

Introduction Von Willebrand factor propeptide (VWF:Ag II) is proposed to be a more sensitive marker of acute endothelial activation than von Willebrand factor antigen (VWF:Ag). Simultaneous data on VWF:Ag and VWF:Ag II profiles are very limited following TIA and ischaemic stroke. Methods In this prospective, observational, case-control study, plasma VWF:Ag and VWF:Ag II levels were quantified in 164 patients ≤ 4 weeks of TIA or ischaemic stroke (baseline), and then ≥ 14 days (14d) and ≥ 90 days (90d) later, and compared with those from 27 healthy controls. TIA and stroke subtyping was performed according to the TOAST classification. The relationship between VWF:Ag and VWF:Ag II levels and platelet activation status was assessed. Results ‘Unadjusted’ VWF:Ag and VWF:Ag II levels were higher in patients at baseline, 14d and 90d than in controls (p ≤ 0.03). VWF:Ag levels remained higher in patients than controls at baseline (p ≤ 0.03), but not at 14d or 90d after controlling for differences in age or hypertension, and were higher in patients at baseline and 90d after controlling for smoking status (p ≤ 0.04). ‘Adjusted’ VWF:Ag II levels were not higher in patients than controls after controlling for age, hypertension or smoking (p ≥ 0.1). Patients with symptomatic carotid stenosis (N = 46) had higher VWF:Ag and VWF:Ag II levels than controls at all time-points (p ≤ 0.002). There was no significant correlation between platelet activation status and VWF:Ag or VWF:Ag II levels. Conclusions VWF:Ag and VWF:Ag II levels are increased in an overall TIA and ischaemic stroke population, especially in patients with recently symptomatic carotid stenosis. VWF:Ag II was not superior to VWF:Ag at detecting acute endothelial activation in this cohort and might reflect timing of blood sampling in our study.