title: Recurrent venous thromboembolism in patients with and without anticoagulation after inferior vena caval filter placement.
abstract: OBJECTIVE
  The aim of this study was to compare the rate of recurrent venothromboembolic (VTE) events and factors contributing to VTE events in patients with inferior vena caval (IVC) filters on chronic anticoagulation to those in whom anticoagulation was discontinued.
  
  
  METHODS
  Retrospective cohort study of 353 patients who received IVC filters between 1986 and 2002.
  
  
  RESULTS
  Anticoagulation status was available for 304 patients (132 on coumadin anticoagulation therapy and 172 who did not receive any anticoagulation therapy) whose IVC filters were placed within 30 days of their qualifying thromboembolic event. Two-year event-free survival for the anticoagulated group was 80.6% (95% confidence interval--CI--76.9, 84.3] and was 67.8% (95% CI 63.2, 72.3) for the non-anticoagulated group. Patients who had Greenfield filter had a higher, but not statistically significant different, rate of recurrence compared to those with other types of filters (hazard ratio 1.4; 95% CI 0.9, 2). The rate of recurrent VTE events was independent of age, gender, smoking status, or underlying medical condition.
  
  
  CONCLUSIONS
  Among those with IVC filters, long-term anticoagulation therapy prolonged event-free survival for up to 2 years but did not prevent recurrent VTE events.
authors.affiliation: Department of Internal Medicine, Marshfield Clinic, Marshfield, WI 54449, USA. yale.steven@mcrf.mfldclin.edu
authors.forename: S H
authors.initials: SH
authors.lastname: Yale
authors.forename: J J
authors.initials: JJ
authors.lastname: Mazza
authors.forename: I
authors.initials: I
authors.lastname: Glurich
authors.forename: T
authors.initials: T
authors.lastname: Peters
authors.forename: B N
authors.initials: BN
authors.lastname: Mukesh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012008:Recurrence; D012189:Retrospective Studies; D016019:Survival Analysis; D013923:Thromboembolism / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome; D016306:Vena Cava Filters; D020246:Venous Thrombosis / Q000401:mortality / Q000628:therapy*; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin