Risk of recurrent venous thromboembolism in patients with the factor V Leiden (FVR506Q) mutation: effect of warfarin and prediction by precipitating factors. East Anglian Thrombophilia Study Group

Br J Haematol. 1998 Mar;100(4):764-8. doi: 10.1046/j.1365-2141.1998.00632.x.


Three cohorts of patients with the factor V Leiden mutation were recruited independently (heterozygotes, homozygotes and combined thrombophilia). The antithrombotic efficacy of oral anticoagulation and the predictive value for recurrence of an idiopathic as opposed to a precipitated first event were determined. Idiopathic first events occurred at an older age than precipitated events (43 v 26 years, LR = 23.31, P < 0.001). None of the patients had a recurrent event while on warfarin but the median time to recurrence after stopping warfarin was 9 years (95% CI 0.7-17.3 years). The time to recurrence was shorter when the first event was idiopathic as opposed to precipitated (3.5 v 13 years, LR = 4.76, P = 0.029). A calculation of benefit to risk of oral anticoagulation with a target INR of 2.5 does not support the use of long-term therapy in all patients with the factor V Leiden mutation following a first thrombotic event.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Anticoagulants / therapeutic use*
  • Child
  • Factor V / genetics*
  • Female
  • Heterozygote
  • Homozygote
  • Humans
  • Male
  • Middle Aged
  • Mutation*
  • Recurrence
  • Thromboembolism / drug therapy
  • Thromboembolism / genetics*
  • Time Factors
  • Warfarin / therapeutic use*


  • Anticoagulants
  • factor V Leiden
  • Warfarin
  • Factor V