title: D-dimer levels and recurrence in patients with unprovoked VTE and a negative qualitative D-dimer test after treatment.
abstract: BACKGROUND
  The rate of recurrent venous thromboembolism (VTE) in patients with a first unprovoked VTE who had a negative qualitative D-dimer test one month after stopping anticoagulant therapy was higher than expected in the D-dimer Optimal Duration Study (DODS).
  
  
  OBJECTIVE
  To determine whether quantitative D-dimer levels using a low threshold, age- and sex-specific thresholds, or repeated measurements, would improve identification of patients at low risk of recurrent VTE.
  
  
  METHODS
  D-dimer levels were quantified in banked samples from 307 patients in DODS who had a negative qualitative D-dimer test while on, and 1month after stopping, anticoagulant therapy and the rates of recurrent VTE were determined in patients with D-dimer levels below various predefined thresholds.
  
  
  RESULTS
  The rate (per patient year) of recurrent VTE was: 5.9% with D-dimer levels<250μg/l at one month; 5.2% with D-dimer levels between 250 and 499μg/l at one month; 5.0% with D-dimer levels less than predefined age- and sex-specific thresholds at one month; and 6.3% when D-dimer levels were <500μg/l at both one and 7months after stopping anticoagulant therapy. These rates are similar to the overall event rate of 6.3% in patients who stopped treatment.
  
  
  CONCLUSIONS
  Among unprovoked VTE patients who had a negative qualitative D-dimer test during and after anticoagulant therapy, low D-dimer thresholds, age and sex-adjusted thresholds or repeated measurements, did not identify subgroups with a very low rate of recurrence.
authors.affiliation: McMaster University, Hamilton, Ontario, Canada. Electronic address: kearonc@mcmaster.ca.
authors.forename: C
authors.initials: C
authors.lastname: Kearon
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Parpia
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: F A
authors.initials: FA
authors.lastname: Spencer
authors.affiliation: Addenbrooke's Hospital, Cambridge, UK.
authors.forename: T
authors.initials: T
authors.lastname: Baglin
authors.affiliation: Intermountain Medical Center, Murray, UT, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Stevens
authors.affiliation: Harvard Medical School, Boston, MA, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Bauer
authors.affiliation: University of Iowa, Iowa City, IA, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Lentz
authors.affiliation: Georgetown University, Washington, DC, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Kessler
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: J D
authors.initials: JD
authors.lastname: Douketis
authors.affiliation: University of North Carolina, Chapel Hill, NC, USA.
authors.forename: S
authors.initials: S
authors.lastname: Moll
authors.affiliation: Hurley Medical Center, Flint, MI, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kaatz
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Schulman
authors.affiliation: Harvard Medical School, Boston, MA, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Connors
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: J S
authors.initials: JS
authors.lastname: Ginsberg
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Spadafora
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: P C
authors.initials: PC
authors.lastname: Liaw
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: J I
authors.initials: JI
authors.lastname: Weitz
authors.affiliation: McMaster University, Hamilton, Ontario, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Julian
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D011379:Prognosis; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000188:drug therapy*
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: Cohort study; D-dimer; Forecasting; Prognosis; Venous thrombosis