Intended for healthcare professionals

Clinical Review

Diagnosis, investigation, and management of deep vein thrombosis

BMJ 2003; 326 doi: https://doi.org/10.1136/bmj.326.7400.1180 (Published 29 May 2003) Cite this as: BMJ 2003;326:1180

Lifetime Warfarin Prophylaxis Against Recurrent VTE

The trial of Kearon and the ELATE investigators(1) comparing
conventional warfarin with low-intensity warfarin for extended venous
thromboembolism (VTE) prophylaxis concluded that lifetime conventional
warfarin should become the standard of care for those with idiopathic VTE.

I disagree. The PREVENT trial(2) comparing low-intensity warfarin with
placebo was inadequate to prove that long-term low-intensity warfarin
should become the standard of care.(3) Therefore, to assess benefits
versus risks of lifetime adjusted dose warfarin as a new therapy, an
untreated control group must be included in the trial. In the recent
trial, 1% and 0% of patients had major and fatal bleeding each year,
respectively. However, two meta-analyses of prospective studies involving
conventional warfarin found the average yearly rates of bleeding to be
higher (major = 1.7%(4) and 3.0%(5), fatal = 0.8%(4) and 0.6%(5)).

Consequently, for each 100,000 VTE patients on extended warfarin
treatment, the meta-analyses bleeding rates translate to 1,700 – 3,000
major hemorrhages and 600 – 800 bleeding deaths per year. No trial of
extended warfarin for VTE has shown a significant reduction in fatal PE.
The risks of extended warfarin for VTE outweigh the benefits.

Sincerely,

David K. Cundiff

1. Kearon C, Ginsberg JS, Kovacs MJ, et al. Comparison of Low-
Intensity Warfarin Therapy with Conventional-Intensity Warfarin Therapy
for Long-Term Prevention of Recurrent Venous Thromboembolism. The Extended
Low-Intensity Anticoagulation for Thrombo-Embolism Investigators. N Engl J
Med 2003; 349:631-639.

2. Ridker PM, Goldhaber SZ, Danielson E, et al. Long-Term, Low-
Intensity Warfarin Therapy for the Prevention of Recurrent Venous
Thromboembolism. N Engl J Med 2003; 348:1425-34.

http://content.nejm.org/cgi/content/abstract/NEJMoa035029v1.

3. Cundiff DK. Insufficient evidence supporting low-intensity warfarin for
venous thromboembolism (VTE) prophylaxis--Commentary. MedGenMed 2003;
5:http://www.medscape.com/viewarticle/457570.

4. Levine MN, Hirsh J, Landefeld S, Raskob G. Hemorrhagic
complications of anticoagulant treatment. Chest 1992; 102:352S-363S.

5. Landefeld CS, Beyth RJ. Anticoagulant-related bleeding: clinical
epidemiology, prediction, and prevention. American Journal of Medicine
1993; 95:315-28.

Competing interests:  
I lost my license to practice medicine in the United States because I stopped warfarin treatment of an alcoholic with a DVT.

Competing interests: No competing interests

07 October 2003
David K. Cundiff
None
2111 Bermuda St. Apt 8, Long Beach, CA 90814 USA