title: Time course of acquired von Willebrand disease associated with two types of continuous-flow left ventricular assist devices: HeartMate II and CircuLite Synergy Pocket Micro-pump.
abstract: BACKGROUND
  Bleeding complications are frequent adverse events in patients supported with axial continuous-flow pumps. Previous retrospective studies demonstrated that bleeding events in patients with the HeartMate II (Thoratec Corp, Pleasanton, CA) were attributed to acquired von Willebrand syndrome. We sought to analyze the von Willebrand factor (VWF) profile in patients receiving a HeartMate II or a CircuLite (Saddle Brook, NJ,) device (Synergy Pocket Micro-pump) prospectively.
  
  
  METHODS
  Prospectively analyzed were 34 patients supported with left ventricular assist device (LVAD; 26 with HeartMate II and 8 with CircuLite). The control group comprised 20 patients who underwent heart transplantation (HTx). Blood samples were taken pre-operatively and at 14 days and 3, 6, 9, and 12 months post-operatively.
  
  
  RESULTS
  Patients with LVADs had a high incidence of bleeding complications. From the immediate post-operative phase throughout the entire observation, the VWF ristocetin cofactor activity (Rco)/antigen (Ag) ratio of patients with HeartMate II and CircuLite devices was consistently lower compared with HTx patients. No correlation was found between the individual VWF:Rco/Ag ratio and bleeding events or transfusion requirements. The VWF:Rco/Ag ratio normalized immediately in patients who received HTx.
  
  
  CONCLUSIONS
  Acquired von Willebrand syndrome was confirmed to occur immediately after the implantation of both types of LVAD and persisted up to 12 months. A lower VWF:Rco/Ag ratio was associated with larger transfusion requirements. Acquired von Willebrand syndrome resolves after LVAD explantation.
authors.affiliation: Department of Cardiac Surgery, University Hospital Leuven, Belgium.
authors.forename: Motohiko
authors.initials: M
authors.lastname: Goda
authors.forename: Steven
authors.initials: S
authors.lastname: Jacobs
authors.forename: Filip
authors.initials: F
authors.lastname: Rega
authors.forename: Kathelijne
authors.initials: K
authors.lastname: Peerlinck
authors.forename: Marc
authors.initials: M
authors.lastname: Jacquemin
authors.forename: Walter
authors.initials: W
authors.lastname: Droogne
authors.forename: Johan
authors.initials: J
authors.lastname: Vanhaecke
authors.forename: Johan
authors.initials: J
authors.lastname: Van Cleemput
authors.forename: Klaartje
authors.initials: K
authors.lastname: Van den Bossche
authors.forename: Bart
authors.initials: B
authors.lastname: Meyns
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D016027:Heart Transplantation; D006353:Heart-Assist Devices / Q000009:adverse effects* / Q000145:classification*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult; D014842:von Willebrand Diseases / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D014841:von Willebrand Factor / Q000276:immunology / Q000378:metabolism
chemical_list: D006454:Hemoglobins; C029417:Von Willebrand antigen; D014841:von Willebrand Factor