Von Willebrand Factor Drives the Association Between Elevated Factor VIII and Poor Outcomes in Patients With Ischemic Stroke

BACKGROUND AND PURPOSE: Despite clear roles of factor VIII (FVIII) and von Willebrand factor (vWF) in thrombosis, few studies have examined the relationship of these factors with acute ischemic stroke (AIS). We sought to determine whether concurrent elevation in FVIII and vWF was associated with adverse events and outcomes. METHODS: From our prospective stroke registry, patients consecutively admitted with AIS between July 2008 and October 2013 were included if both FVIII and vWF were measured during admission. The primary outcome was the modified Rankin Scale score on discharge. RESULTS: Among 1453 cases in our stroke registry, 148 patients with AIS met inclusion criteria; 62 patients (41.9%) had FVIII-/vWF-, 16 patients (10.8%) had FVIII+/vWF-, and 51 patients (34.5%) had FVIII+/vWF+. In the fully adjusted model, patients with FVIII+/vWF+ had increased odds of inpatient complications (odds ratio, 8.6; 95% confidence interval, 1.58-46.85; P=0.013) and neuroworsening (odds ratio, 3.2; 95% confidence interval, 1.18-8.73; P=0.022) than patients with FVIII-/vWF-. Adjusted for age, baseline stroke severity, and glucose, patients with FVIII+/vWF+ had increased odds of poor functional outcome (modified Rankin Scale>2; odds ratio, 2.87; 95% confidence interval, 1.16-7.06; P=0.021) than patients with FVIII-/vWF-. CONCLUSIONS: Concurrent FVIII/vWF elevation predicts higher odds of inpatient complications, neuroworsening, and worse functional outcomes for patients with AIS compared with patients with normal levels. Our findings suggest that FVIII and vWF levels may serve as clinically useful stroke biomarkers by providing risk profiles for patients with AIS.