D-dimer, factor VIII coagulant activity, low-intensity warfarin and the risk of recurrent venous thromboembolism

J Thromb Haemost. 2006 Jun;4(6):1208-14. doi: 10.1111/j.1538-7836.2006.01935.x.


Background: Elevated plasma D-dimer and factor VIII coagulant activity (FVIIIc) may be associated with the risk of recurrent venous thromboembolism (VTE).

Objectives: To evaluate D-dimer and FVIIIc as risk factors for recurrent VTE and assess the efficacy of extended low-intensity warfarin (target International Normalized Ratio 1.5-2.0) in preventing recurrence by biomarker level.

Patients and methods: In the Prevention of Recurrent Venous Thromboembolism trial, 508 idiopathic VTE patients treated for > or = 3 months with full-intensity warfarin, and who had stopped warfarin for 7 weeks on average, were randomized to low-intensity warfarin or placebo and followed for 2.1 years for recurrent VTE. Prerandomization blood samples were analysed for D-dimer and FVIIIc.

Results: One-third of participants had elevated baseline D-dimer (> or = 500 ng mL(-1)) and one-fourth, elevated FVIIIc (> or = 150 IU dL(-1)). Adjusting for other risk factors, the hazard ratios (HRs) for recurrent VTE with elevated D-dimer or FVIIIc were 2.0 [95% confidence interval (CI) 1.2-3.4] and 1.5 (95% CI 0.8-2.8), respectively. The association of elevated D-dimer with recurrence was larger among patients with one prior VTE (HR 3.2, 95% CI 1.3-8.0) than in patients with more than one event (HR 1.4, 95% CI 0.7-2.2). For patients with one prior VTE on placebo, the annual recurrence incidence was 10.9% with elevated D-dimer and 2.9% with normal values. Low-intensity warfarin was equally effective in recurrence risk reduction in those with normal or elevated biomarkers.

Conclusions: Among patients with idiopathic VTE, measurement of D-dimer, but not FVIIIc, might be useful for risk stratification. The efficacy of extended low-intensity warfarin therapy did not vary by biomarker level.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anticoagulants / administration & dosage
  • Anticoagulants / therapeutic use*
  • Biomarkers / blood
  • Double-Blind Method
  • Drug Administration Schedule
  • Factor VIII / metabolism
  • Female
  • Fibrin Fibrinogen Degradation Products / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Secondary Prevention
  • Thromboembolism / blood
  • Thromboembolism / drug therapy
  • Thromboembolism / prevention & control*
  • Venous Thrombosis / blood
  • Venous Thrombosis / drug therapy
  • Venous Thrombosis / prevention & control*
  • Warfarin / administration & dosage
  • Warfarin / therapeutic use*


  • Anticoagulants
  • Biomarkers
  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D
  • Warfarin
  • F8 protein, human
  • Factor VIII