title: Conservative perioperative anticoagulation management in patients with chronic venous thromboembolic disease: a cohort study.
abstract: BACKGROUND
  Guidelines for perioperative warfarin management in patients with venous thromboembolic disease (VTE) are largely based on expert opinion.
  
  
  OBJECTIVE
  To assess the effectiveness and safety of a conservative perioperative anticoagulation strategy in patients with VTE on chronic warfarin therapy. Our center uses a conservative bridging approach for chronic VTE patients consisting of withholding warfarin for 5 days preoperatively, with prophylactic low-molecular-weight heparin (LMWH) post-procedure only if patients are admitted to hospital.
  
  
  METHODS
  We performed a single-center retrospective cohort study. During the study period (1997-2011) there were 634 procedures in 416 patients that were reviewed for postoperative outcomes at 30 and 90 days.
  
  
  RESULTS
  Of the 634 procedures, 156 procedures (24.6%) were completed as inpatients. Pre- and post-procedure LMWH bridging was used in 15 (2.4%) and 152 (24.0%) of all procedures, respectively. The 30-day VTE incidence was 0.32% (95% confidence interval [CI] 0.087-1.14), all non-fatal DVTs. The 30-day incidence of major and total bleeding events was 1.26% (95% CI 0.64-2.47) and 3.00% (95% CI 1.93-4.63), respectively. The all-cause mortality rate was 0.32% (95% CI 0.087-1.14) at 30 days; two patients died from arterial thrombosis events.
  
  
  CONCLUSIONS
  A randomized controlled trial is needed to provide definitive conclusions but a conservative bridging approach appears promising.
authors.affiliation: Department of Medicine, Division of Hematology, London Health Sciences Centre, London, ON Department of Epidemiology and Biostatistics, University of Western Ontario, London, ON, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Skeith
authors.forename: J
authors.initials: J
authors.lastname: Taylor
authors.forename: A
authors.initials: A
authors.lastname: Lazo-Langner
authors.forename: M J
authors.initials: MJ
authors.lastname: Kovacs
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage*; D002908:Chronic Disease; D005260:Female; D006470:Hemorrhage; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage; D006801:Humans; D015994:Incidence; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D059035:Perioperative Period; D011184:Postoperative Period; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000188:drug therapy* / Q000453:epidemiology; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D014859:Warfarin