title: D-dimer testing to select patients with a first unprovoked venous thromboembolism who can stop anticoagulant therapy: a cohort study.
abstract: BACKGROUND
  Normal D-dimer levels after withdrawal of anticoagulant therapy are associated with a reduced risk for recurrence in patients with unprovoked venous thromboembolism (VTE) and may justify stopping treatment.
  
  
  OBJECTIVE
  To determine whether patients with a first unprovoked VTE and negative D-dimer test result who stop anticoagulant therapy have a low risk for recurrence.
  
  
  METHODS
  Prospective management study with blinded outcome assessment. (ClinicalTrials.gov: NCT00720915).
  
  
  METHODS
  13 university-affiliated clinical centers.
  
  
  METHODS
  410 adults aged 75 years or younger with a first unprovoked proximal deep venous thrombosis or pulmonary embolism who had completed 3 to 7 months of anticoagulant therapy.
  
  
  METHODS
  Anticoagulant therapy was stopped if D-dimer test results were negative and was not restarted if results were still negative after 1 month.
  
  
  METHODS
  Recurrent VTE during an average follow-up of 2.2 years.
  
  
  RESULTS
  In 319 patients (78%) who had 2 negative D-dimer results and did not restart anticoagulant therapy, rates of recurrent VTE were 6.7% (95% CI, 4.8% to 9.0%) per patient-year overall (42 of 319), 9.7% (CI, 6.7% to 13.7%) per patient-year in men (33 of 180), 5.4% (CI, 2.5% to 10.2%) per patient-year in women with VTE not associated with estrogen therapy (9 of 81), and 0.0% (CI, 0.0% to 3.0%) per patient-year in women with VTE associated with estrogen therapy (0 of 58) (P = 0.001 for the 3-group comparison).
  
  
  CONCLUSIONS
  Imprecision in female subgroups. Results may not be generalizable to different D-dimer assays from the one used in the study.
  
  
  CONCLUSIONS
  The risk for recurrence in patients with a first unprovoked VTE who have negative D-dimer results is not low enough to justify stopping anticoagulant therapy in men but may be low enough to justify stopping therapy in women.
  
  
  BACKGROUND
  Canadian Institutes of Health Research.
authors.forename: Clive
authors.initials: C
authors.lastname: Kearon
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Spencer
authors.forename: Denis
authors.initials: D
authors.lastname: O'Keeffe
authors.forename: Sameer
authors.initials: S
authors.lastname: Parpia
authors.forename: Sam
authors.initials: S
authors.lastname: Schulman
authors.forename: Trevor
authors.initials: T
authors.lastname: Baglin
authors.forename: Scott M
authors.initials: SM
authors.lastname: Stevens
authors.forename: Scott
authors.initials: S
authors.lastname: Kaatz
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Bauer
authors.forename: James D
authors.initials: JD
authors.lastname: Douketis
authors.forename: Steven R
authors.initials: SR
authors.lastname: Lentz
authors.forename: Craig M
authors.initials: CM
authors.lastname: Kessler
authors.forename: Stephan
authors.initials: S
authors.lastname: Moll
authors.forename: Jean M
authors.initials: JM
authors.lastname: Connors
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Ginsberg
authors.forename: Luciana
authors.initials: L
authors.lastname: Spadafora
authors.forename: Jim A
authors.initials: JA
authors.lastname: Julian
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D002423:Cause of Death; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood* / Q000188:drug therapy*; D012008:Recurrence; D012307:Risk Factors; D012737:Sex Factors; D053828:Stockings, Compression; D054556:Venous Thromboembolism / Q000097:blood* / Q000188:drug therapy*; D028761:Withholding Treatment
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors; C036309:fibrin fragment D