title: Low-intensity adjusted-dose warfarin for the prevention of hemodialysis catheter failure: a randomized, controlled trial.
abstract: OBJECTIVE
  To determine whether warfarin prolongs the time to first mechanical-catheter failure.
  
  
  METHODS
  This was a multicenter parallel-group randomized controlled trial with blinding of participants, trial staff, clinical staff, outcome assessors, and data analysts. Randomization was in a 1:1 ratio in blocks of four and was concealed by use of fax to a central pharmacy. Hemodialysis patients with newly-placed catheters received low-intensity monitored-dose warfarin, target international normalized ratio (INR) 1.5 to 1.9, or placebo, adjusted according to schedule of sham INR results. The primary outcome was time to first mechanical-catheter failure (inability to establish a circuit or blood flow less than 200 ml/min).
  
  
  RESULTS
  We randomized 174 patients: 87 to warfarin and 87 to placebo. Warfarin was associated with a hazard ratio (HR) of 0.90 (P=0.60; 95% confidence interval [CI], 0.57, 1.38) for time to first mechanical-catheter failure. Secondary analyses were: time to first guidewire exchange or catheter removal for mechanical failure (HR 0.78; 95% CI, 0.37, 1.6); time to catheter removal for mechanical failure (HR 0.67; 95% CI, 0.19, 2.37); and time to catheter removal for any cause (HR 0.89; 95% CI, 0.42, 1.81). Major bleeding occurred in 10 participants assigned to warfarin and seven on placebo (relative risk, 1.43; 95% CI, 0.57, 3.58; P=0.61).
  
  
  CONCLUSIONS
  We found no evidence for efficacy of low-intensity, monitored-dose warfarin in preventing mechanical-catheter failure.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Wilkieson
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Ingram
authors.forename: Mark A
authors.initials: MA
authors.lastname: Crowther
authors.forename: Steven D
authors.initials: SD
authors.lastname: Soroka
authors.forename: Ryuta
authors.initials: R
authors.lastname: Nagai
authors.forename: Kailash K
authors.initials: KK
authors.lastname: Jindal
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Clase
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage*; D002405:Catheterization, Central Venous / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D006435:Renal Dialysis / Q000379:methods*; D016896:Treatment Outcome; D056824:Upper Extremity Deep Vein Thrombosis / Q000517:prevention & control*; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D010919:Placebos; D014859:Warfarin