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

ABSTRACT

INTRODUCTION: Von Willebrand factor propeptide (VWFAg II) is proposed to be a more sensitive marker of acute endothelial activation than von Willebrand factor antigen (VWFAg). Simultaneous data on VWFAg and VWFAg II profiles are very limited following TIA and ischaemic stroke. METHODS: In this prospective, observational, case-control study, plasma VWFAg and VWFAg II levels were quantified in 164 patients≤4weeks of TIA or ischaemic stroke (baseline), and then ≥14days (14d) and ≥90days (90d) later, and compared with those from 27 healthy controls. TIA and stroke subtyping was performed according to the TOAST classification. The relationship between VWFAg and VWFAg II levels and platelet activation status was assessed. RESULTS: 'Unadjusted' VWFAg and VWFAg II levels were higher in patients at baseline, 14d and 90d than in controls (p≤0.03). VWFAg 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' VWFAg 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 VWFAg and VWFAg II levels than controls at all time-points (p≤0.002). There was no significant correlation between platelet activation status and VWFAg or VWFAg II levels. CONCLUSIONS: VWFAg and VWFAg II levels are increased in an overall TIA and ischaemic stroke population, especially in patients with recently symptomatic carotid stenosis. VWFAg II was not superior to VWFAg at detecting acute endothelial activation in this cohort and might reflect timing of blood sampling in our study.