title: 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.
authors.affiliation: Haemostasis, Thrombosis and Vascular Biology Unit, University Department of Medicine, City Hospital, Birmingham B18 7QH, UK.
authors.forename: Bethan
authors.initials: B
authors.lastname: Freestone
authors.forename: Aun Yeong
authors.initials: AY
authors.lastname: Chong
authors.forename: Hoong Sern
authors.initials: HS
authors.lastname: Lim
authors.forename: Andrew
authors.initials: A
authors.lastname: Blann
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
mesh_terms: D000368:Aged; D043925:Angiogenesis Inducing Agents / Q000097:blood / Q000378:metabolism*; D042702:Angiopoietin-2 / Q000097:blood; D001281:Atrial Fibrillation / Q000503:physiopathology*; D004727:Endothelium / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013925:Thromboplastin / Q000032:analysis / Q000096:biosynthesis; D013927:Thrombosis / Q000503:physiopathology*; D042461:Vascular Endothelial Growth Factor A / Q000097:blood; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D043925:Angiogenesis Inducing Agents; D042702:Angiopoietin-2; D042461:Vascular Endothelial Growth Factor A; D014841:von Willebrand Factor; D013925:Thromboplastin