title: Elevated D-dimer levels predict recurrence in patients with idiopathic venous thromboembolism: a meta-analysis.
abstract: BACKGROUND
  The evidence on the optimal duration of treatment in patients with an idiopathic venous thromboembolic event (VTE) is inconclusive. d-dimer testing to predict recurrent VTE has been evaluated in several studies.
  
  
  OBJECTIVE
  We performed a meta-analysis of studies of patients with idiopathic VTE treated with oral anticoagulation therapy (OAT) to assess the prognostic value of elevated D-dimer levels 1 month after discontinuation of OAT for VTE recurrence.
  
  
  METHODS
  The MEDLINE, EMBASE and Cochrane databases were searched to identify relevant studies. Studies were eligible for inclusion if they included patients with idiopathic VTE and in addition reported results for this group separately, had measured D-dimer approximately 1 month after discontinuation of OAT and had reported on recurrence of VTE. A random-effects model was used to pool study results.
  
  
  RESULTS
  Data from four studies (1539 patients) were included in the current analysis. All studies reported on the number of recurrent events in the normal and elevated D-dimer groups. Overall, 125 of 751 patients (16.6%) with elevated D-dimer levels experienced recurrent VTE during the period of follow-up compared with 57 of 788 patients (7.2%) with normal D-dimer levels. Elevated D-dimer levels were significantly associated with recurrent VTE (odds ratio , 2.36; 95% CI, 1.65 to 3.36).
  
  
  CONCLUSIONS
  Elevated d-dimer levels measured 1 month after discontinuation of OAT identify patients with idiopathic VTE at higher risk of recurrence.
authors.affiliation: Leiden University Medical Center, Section of Vascular Medicine, Department of General Internal Medicine-Endocrinology, Leiden, the Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Bruinstroop
authors.forename: F A
authors.initials: FA
authors.lastname: Klok
authors.forename: M A
authors.initials: MA
authors.lastname: Van De Ree
authors.forename: F L
authors.initials: FL
authors.lastname: Oosterwijk
authors.forename: M V
authors.initials: MV
authors.lastname: Huisman
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D003625:Data Collection; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D012008:Recurrence; D054556:Venous Thromboembolism / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D