title: Aortic stenosis and acquired von Willebrand disease: lack of association.
abstract: OBJECTIVE
  The association between aortic stenosis (AS) and acquired von Willebrand disease type 2A has been described. It may be present in up to 90% of patients with AS. Shear stress has been proposed as the underlying mechanism; however, the physiopathology of this condition is not completely understood. No specific treatment has been studied in this specific population besides aortic valve replacement (AVR). As a coadjuvant therapy, some cardiac surgery centers use desmopressin routinely. The authors report the first stage of an ongoing study designed to compare the effects of desmopressin versus placebo in patients with severe AS scheduled for AVR. Because of the different incidences of the acquired von Willebrand type 2A reported in the literature, the first stage was conducted to describe the incidence of this clinical association in the present population, allowing the sample size for the second stage of the study to be obtained.
  
  
  METHODS
  A prospective cohort study.
  
  
  METHODS
  A single academic medical center.
  
  
  METHODS
  Thirteen patients with severe AS scheduled for AVR.
  
  
  METHODS
  None.
  
  
  RESULTS
  Patients with severe AS scheduled for AVR were studied preoperatively with a von Willebrand laboratory panel. Results were negative for acquired von Willebrand disease type 2A in all patients. The second stage of the trial was stopped.
  
  
  CONCLUSIONS
  Contrary to previous reports, no correlation was found between AS and acquired von Willebrand disease type 2A. Further studies are needed to ascertain whether this lack of association is caused by a specific characteristic of the present population, the small sample size, or other factors.
authors.affiliation: Division of Anesthesiology, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Carrasco
authors.forename: Rodrigo
authors.initials: R
authors.lastname: López
authors.forename: Marcos
authors.initials: M
authors.lastname: Rattalino
authors.forename: Guillermo
authors.initials: G
authors.lastname: Lema
authors.forename: Jaime
authors.initials: J
authors.lastname: Pereira
authors.forename: Roberto
authors.initials: R
authors.lastname: Canessa
authors.forename: Ricardo
authors.initials: R
authors.lastname: Zalaquett
authors.forename: Claudia
authors.initials: C
authors.lastname: Carvajal
authors.forename: Paulo
authors.initials: P
authors.lastname: Carrasco
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000097:blood / Q000150:complications* / Q000601:surgery; D001792:Blood Platelets / Q000502:physiology; D015331:Cohort Studies; D019918:Heart Valve Prosthesis Implantation; D006487:Hemostasis; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D014842:von Willebrand Diseases / Q000453:epidemiology / Q000209:etiology*