LAFIT

Long-term Anticoagulation for a First episode of Idiopathic venous Thromboembolism (1999)

Condition

Long-term prevention of recurrent idiopathic VTE

Close this section

Objective

To determine the effects of extending a 3-month course of oral anticoagulant therapy for a further 24 months on the rates of recurrent symptomatic VTE and bleeding in patients with a first episode of idiopathic VTE

Close this section

Trial design

Randomized, double-blind study
Active treatment: continuation of warfarin therapy (target INR 2.0–3.0) for a further 24 months (n=79)
Control treatment: placebo (n=83) 

Close this section

Endpoints

Primary efficacy endpoint: symptomatic, objectively confirmed recurrence of VTE
Primary safety endpoints: major and minor bleeding, all-cause death

Close this section

Trial participants

162 consecutive patients (mean age 59 years) with a first episode of idiopathic VTE who had completed 3 uninterrupted months of oral anticoagulant treatment after an initial course of treatment with UFH or LMWH

Close this section

Results

Efficacy outcome: Of the 79 patients assigned to continue warfarin, one had a confirmed episode of recurrent VTE (1.3% per patient-year), as compared with 17 of 83 patients given placebo (27.4% per patient-year). This resulted in a relative risk reduction of 95%. All episodes of recurrent VTE were idiopathic
Safety outcome: Major bleeding occurred in 3 patients assigned to warfarin (3.8% per patient-year) and no such episodes among those receiving placebo. Minor bleeding occurred in 7.7% and 1.4% per patient-years, respectively. One patient in the warfarin group and 3 patients in the placebo group died during the study (1.2% vs. 4.1% per patient-year)

Close this section

Summary

Efficacy: The clinical benefit achieved during the additional 24 months of oral anticoagulant therapy was significant. Therefore patients with a first episode of idiopathic VTE should be treated with anticoagulants for longer than 3 months
Safety: Extended warfarin therapy was associated with a risk of major bleeding of about 3% per year

Close this section

Reference

Kearon C, Gent M, Hirsh J, Weitz J, Kovacs MJ, Anderson DR, Turpie AG, Green D, Ginsberg JS, Wells P, MacKinnon B, Julian JA. A comparison of three months of anticoagulation with extended anticoagulation for a first episode of idiopathic venous thromboembolism. N Engl J Med 1999;340:901-907

Close this section

Corresponding author

Clive Kearon, MD, Hamilton Health Sciences Corporation, Henderson Division, 711 Concession St., Hamilton, ON L8V 1C3, Canada

Close this section

Back To List

Recommend pageBack to top