Angiogenic factors in atrial fibrillation: A possible role in thrombogenesis?

Abstract

Background. The precise pathophysiological processes underlying the prothrombotic or hypercoagulable state in atrial fibrillation (AF) remain uncertain. We hypothesized a relationship between abnormal endothelial damage/dysfunction, coagulation, and angiogenic factors, thereby contributing to increased thrombogenicity.Methods. Plasma levels of von Willebrand factor (vWF, an index of endothelial damage/dysfunction) and tissue factor (TF, an index of coagulation), as well as the angiogenic factors, vascular endothelial growth factor (VEGF), angiopoietin‐1 (Ang‐1) and angiopoietin‐2 (Ang‐2), were measured by enzyme‐linked immunosorbant assay (ELISA) in 59 chronic AF patients. Data were compared to 40 age‐ and sex‐matched healthy controls in sinus rhythm.Results. Plasma vWF, VEGF and Ang‐2 were significantly higher in AF patients compared to healthy controls (P = 0.005, P = 0.0055 and P<0.0001 respectively) but there were no significant differences in plasma Ang‐1 or TF levels between the two groups (P = 0.925 and P = 0.121 respectively). Significant correlations were found between VEGF and vWF levels (Spearman, r = 0.262, P = 0.011) and between VEGF and Ang‐2 (r = 0.333, P = 0.001).Conclusions. Raised VEGF in association with Ang‐2 and vWF may reflect a link between abnormal endothelial damage/dysfunction and angiogenic factors. These may act together to alter TF expression and endothelial integrity, thereby contributing to the prothrombotic state in AF.