title: Effect of aspirin and warfarin therapy on thromboembolic events in patients with univentricular hearts and Fontan palliation.
abstract: BACKGROUND
  Patients with univentricular hearts and Fontan palliation are at risk for thromboembolic complications. While aspirin and warfarin therapies are currently the mainstay of prophylaxis, controversy exists as to the optimal prevention strategy.
  
  
  METHODS
  A cohort study was conducted on the New England registry of patients born in 1985 or earlier with Fontan surgery at Boston Children's Hospital, in order to assess and compare the effect of prophylactic aspirin and warfarin on incident thromboembolic events.
  
  
  RESULTS
  A total of 210 qualifying patients (49% male) underwent Fontan surgery at a median age of 8.5 years: 48.6% had a right atrium to pulmonary artery anastomosis, 11% a right atrium to right ventricle conduit, 38.6% a lateral tunnel, and 1.9% an extracardiac conduit. No thromboembolic prophylaxis was prescribed to 50.0%, whereas 24.3% received aspirin, and 25.7% warfarin. In multivariate analyses, lack of aspirin or warfarin was associated with a significantly higher thromboembolic event rate when compared to therapy with either [hazard ratio 8.5, 95% confidence interval (3.6-19.9), P < 0.001], with no difference between the two treatment strategies (P = 0.768). Twenty-year freedom from thromboemboli was 86% versus 52% in patients with and without thromboprophylaxis, respectively. Other factors independently associated with thromboemboli were a low post-operative cardiac index [hazard ratio 2.6, 95% confidence interval (1.2, 5.9)] and atrial fibrillation or flutter [hazard ratio 3.1, 95% confidence interval (1.2, 8.0)].
  
  
  CONCLUSIONS
  Prophylaxis with either aspirin or warfarin was associated with a significantly lower rate of incident thromboembolic events following Fontan palliation, with no difference between the two therapies.
authors.affiliation: Harvard School of Public Health, Boston, MA, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Potter
authors.forename: Peter
authors.initials: P
authors.lastname: Leong-Sit
authors.forename: Susan M
authors.initials: SM
authors.lastname: Fernandes
authors.forename: Andrew
authors.initials: A
authors.lastname: Feifer
authors.forename: John E
authors.initials: JE
authors.lastname: Mayer
authors.forename: John K
authors.initials: JK
authors.lastname: Triedman
authors.forename: Edward P
authors.initials: EP
authors.lastname: Walsh
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Landzberg
authors.forename: Paul
authors.initials: P
authors.lastname: Khairy
mesh_terms: D000293:Adolescent; D001241:Aspirin / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000009:adverse effects* / Q000639:trends; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities / Q000601:surgery*; D006801:Humans; D008297:Male; D012042:Registries; D013923:Thromboembolism / Q000188:drug therapy* / Q000453:epidemiology; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D014859:Warfarin; D001241:Aspirin
keywords: Anticoagulation; Aspirin; Fontan; Thromboembolism; Thrombus; Warfarin