Is von Willebrand factor associated with stroke and death at mid-term in patients with non-valvular atrial fibrillation?

ABSTRACT

BACKGROUND: Heart failure and atrial fibrillation share common mechanisms that may contribute to hypercoagulability and thrombotic risk. Elevated von Willebrand factor (vWF) concentration has been associated with increased risk of thromboembolism and cardiovascular events. AIM: To investigate whether increased vWF plasma concentration predicts occurrence of a composite endpoint (all-cause death and stroke) in patients with non-valvular atrial fibrillation (NVAF). METHODS: We prospectively studied 122 patients (mean age 70±14years; 46% men) hospitalized with NVAF, and followed over a median (interquartile range) of 5.4 (2.3-9.0)years. Cox proportional models were used to estimate the association of vWF concentration with time to stroke and death. RESULTS: Forty-three patients (35%) had at least a stroke or died during the 5-year follow-up. Kaplan-Meier curves using vWF plasma concentration tertiles (≤191IU/dL;>191 to≤295IU/dL;>295IU/dL) showed that vWF plasma concentrations discriminated groups of patients with higher cardiovascular event rates (log-rank P=0.01). In the multivariable analysis, higher vWF concentrations (middle tertile hazard ratio [HR] 4.59, 95% confidence interval [CI] 1.55-13.50 [P=0.006]; upper tertile HR 4.10, 95% CI 1.43-11.75 [P=0.009]), age≥75years (HR 5.02, 95% CI 1.53-16.49; P=0.008), heart failure (HR 2.05, 1.01-4.19; P=0.048), C-reactive protein, log2 per unit increase (HR 1.29, 95% CI 1.04-1.61; P=0.021), no warfarin at discharge (HR 4.96, 95% CI 2.02-12.20; P<0.0001) and no aspirin at discharge (HR 4.41, 95% CI 1.71-11.97; P=0.002) were independently associated with an increased risk of stroke and all-cause death, whereas female sex was a protective factor (HR 0.35, 0.16-0.78; P=0.01). CONCLUSIONS: High vWF plasma concentrations may discriminate patients with NVAF at greater risk of stroke or all-cause death.