Long-Term, Low-Intensity Warfarin Therapy
for the Prevention of Recurrent Venous Thromboembolism
content.nejm.org
Paul M Ridker, M.D., Samuel Z. Goldhaber, M.D., Ellie Danielson, M.I.A., Yves Rosenberg, M.D., Charles S. Eby, M.D., Steven R. Deitcher, M.D., Mary Cushman, M.D., Stephan Moll, M.D., Craig M. Kessler, M.D., C. Gregory Elliott, M.D., Rolf Paulson, M.D., Turnly Wong, M.D., Kenneth A. Bauer, M.D., Bruce A. Schwartz, M.D., Joseph P. Miletich, M.D., Henri Bounameaux, M.D., Robert J. Glynn, Sc.D., for the PREVENT Investigators
ABSTRACT
Background Standard therapy to prevent recurrent venous thromboembolism includes 3 to 12 months of treatment with full-dose warfarin with a target international normalized ratio (INR) between 2.0 and 3.0. However, for long-term management, no therapeutic agent has shown an acceptable benefit-to-risk ratio.
Methods Patients with idiopathic venous thromboembolism who had received full-dose anticoagulation therapy for a median of 6.5 months were randomly assigned to placebo or low-intensity warfarin (target INR, 1.5 to 2.0). Participants were followed for recurrent venous thromboembolism, major hemorrhage, and death.
Results The trial was terminated early after 508 patients had undergone randomization and had been followed for up to 4.3 years (mean, 2.1). Of 253 patients assigned to placebo, 37 had recurrent venous thromboembolism (7.2 per 100 person-years), as compared with 14 of 255 patients assigned to low-intensity warfarin (2.6 per 100 person-years), a risk reduction of 64 percent (hazard ratio, 0.36 [95 percent confidence interval, 0.19 to 0.67]; P<0.001). Risk reductions were similar for all subgroups, including those with and those without inherited thrombophilia. Major hemorrhage occurred in two patients assigned to placebo and five assigned to low-intensity warfarin (P=0.25). Eight patients in the placebo group and four in the group assigned to low-intensity warfarin died (P=0.26). Low-intensity warfarin was thus associated with a 48 percent reduction in the composite end point of recurrent venous thromboembolism, major hemorrhage, or death. According to per-protocol and as-treated analyses, the reduction in the risk of recurrent venous thromboembolism was between 76 and 81 percent.
Conclusions Long-term, low-intensity warfarin therapy is a highly effective method of preventing recurrent venous thromboembolism.
N Engl J Med 2003;348.
Notice: Because of its potential therapeutic implications, this article, as well as a related editorial, was published at www.nejm.org on February 24, 2003. The article and editorial will appear in the April 10, 2003, issue of the Journal.
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Editorial
Published at www.nejm.org February 24, 2003 (10.1056/NEJMe030018)
Warfarin for Venous Thromboembolism -- Walking the Dosing Tightrope
content.nejm.org
[No abstract - one has to follow the link to the PDF full text]
Has been the regimen of a close relative(outside of any trial). Glad to see new info presented- mfm |
