title: The management of anticoagulants in the periendoscopic period for patients with atrial fibrillation: a decision analysis.
abstract: OBJECTIVE
  The management of patients who undergo endoscopy while being treated with warfarin is challenging. We used decision analysis to determine the preferred strategy to manage anticoagulants in the periendoscopic period.
  
  
  METHODS
  We designed a Markov model to estimate costs and quality-adjusted survival during a 10-year period in patients with nonvalvular atrial fibrillation undergoing screening colonoscopy. We compared six alternatives to the continue-warfarin strategy, which was to perform colonoscopy while the patient was taking full-dose warfarin. The hold-warfarin strategy was to stop warfarin 5 days before the colonoscopy. The repeat endoscopy strategy was to continue warfarin for a diagnostic colonoscopy, followed by a repeat procedure after cessation of warfarin if polypectomy was required. The dose-reduction strategy was to reduce the warfarin dose before colonoscopy. The low molecular weight heparin strategy was to administer subcutaneous low molecular weight heparin for 2 days before and 2 days after colonoscopy. The unfractionated heparin strategy was to administer intravenous unfractionated heparin for 2 days before and 2 days after the procedure. The vitamin K strategy was to hold warfarin for 4 days and to administer vitamin K if the international normalized ratio (INR) exceeded 2.0 the day before the procedure, or low molecular weight heparin if the INR was less than 1.5.
  
  
  RESULTS
  For screening colonoscopy, assuming that polyps would be removed in 35% of examinations, the hold-warfarin and dose-reduction arms were both cost-effective strategies. The hold-warfarin arm was most cost-effective if the likelihood of polypectomy exceeded 60%, or if there was a low risk of stroke despite atrial fibrillation. The continue-warfarin strategy was preferred if the probability of polypectomy was 1% or less.
  
  
  CONCLUSIONS
  Temporary warfarin cessation or halving the warfarin dose for several days before endoscopy was the preferred strategy for most patients. Periendoscopic heparin therapy was not cost-effective for patients with nonvalvular atrial fibrillation.
authors.affiliation: Division of Gastroenterology, Stanford University School of Medicine, California 94305-5202, USA. lgerson@stanford.edu
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Gerson
authors.forename: George
authors.initials: G
authors.lastname: Triadafilopoulos
authors.forename: Brian F
authors.initials: BF
authors.lastname: Gage
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000453:epidemiology; D019468:Disease Management; D016099:Endoscopy, Gastrointestinal; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D015995:Prevalence; D019057:Quality-Adjusted Life Years; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000188:drug therapy / Q000453:epidemiology; D016019:Survival Analysis; D019851:Thrombophilia / Q000139:chemically induced / Q000453:epidemiology; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin