title: Prognostic value of plasma von Willebrand factor and its cleaving protease ADAMTS13 in patients with atrial fibrillation.
abstract: BACKGROUND
  The von Willebrand factor (vWF) is essential for platelet adhesion and arterial thrombosis. It is degraded into less active multimers by ADAMTS13. Patients with atrial fibrillation (AF) exhibit higher plasma vWF and lower ADAMTS13 antigen levels. The vWF/ADAMTS13-ratio might help to estimate the pro-thrombotic risk of patients with AF. We therefore investigated whether a high ratio of vWF/ADAMTS13, independently of clinical risk scores, predicts major adverse cardiovascular events (MACE) in patients with AF.
  
  
  METHODS
  This prospective longitudinal single center study included 269 patients with AF. Blood samples were analyzed for vWF and ADAMTS13-antigen concentration by means of enzyme-linked immunoassay kits.
  
  
  RESULTS
  After adjustment for all univariable predictors for MACE (p ≤ 0.1), ADAMTS13≤49.77% (HR 1.833 (95% CI 1.089-3.086); p=0.023) and vWF/ADAMTS13-ratio>27.57 (HR 2.174 (95% CI 1.238-3.817); p=0.007) remained independently associated with outcome. vWF>1434.92 mU/ml (HR 1.539 (95% CI 0.883-2.682); p=0.128) alone failed to independently predict MACE. In patients with low and intermediate risk for MACE according to the CHADS2-score the addition of high vWF/ADAMTS13-ratio levels (>27.57) had significant impact on the patients' outcome.
  
  
  CONCLUSIONS
  A high ratio of vWF/ADAMTS13 independently predicts MACE in patients with AF. Therefore, vWF and its cleaving protease ADAMTS13 might play an important role in the development and perpetuation of vascular disease in AF patients. This might be a novel target for future treatment strategies or an additional help for risk stratification in AF patients.
authors.affiliation: 3rd Medical Department, Cardiology and Emergency Medicine, Wilhelminenhospital, Vienna, Austria. matthias.freynhofer@meduniwien.ac.at
authors.forename: Matthias K
authors.initials: MK
authors.lastname: Freynhofer
authors.forename: Susanne C
authors.initials: SC
authors.lastname: Gruber
authors.forename: Veronika
authors.initials: V
authors.lastname: Bruno
authors.forename: Thomas
authors.initials: T
authors.lastname: Höchtl
authors.forename: Serdar
authors.initials: S
authors.lastname: Farhan
authors.forename: Vera
authors.initials: V
authors.lastname: Zaller
authors.forename: Johann
authors.initials: J
authors.lastname: Wojta
authors.forename: Kurt
authors.initials: K
authors.lastname: Huber
mesh_terms: D051722:ADAM Proteins / Q000097:blood*; D000071120:ADAMTS13 Protein; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D015415:Biomarkers / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate / Q000639:trends; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D014841:von Willebrand Factor; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human