Test helps identify low risk venous thromboembolism patients

Reported by Susan Aldridge, PhD, medical journalist

A new test can pinpoint which patients with venous thromboembolism are at low risk of recurrence and might not need anticoagulants.
Venous thromboembolism (VTE), the formation of a blood clot in a vein - often in a leg - is generally treated with anticoagulants, which thin the blood. Heparin and vitamin K antagonists are accordingly given for a few months after the event, then discontinued. Some patients then have a recurrence of VTE, which is fatal in five per cent of cases. Clearly this group could benefit from indefinite treatment with anticoagulants. On the other hand, those for whom the risk of recurrent VTE is low are exposed to the side effects of anticoagulants for no good reason.

That is why doctors at the Medical University of Vienna have carried out a study of a lab test that can pinpoint those at low risk of VTE recurrence. They say that those who have low generation of thrombin - a blood protein causing clotting - have minimal risk of recurrence. They identified a group whose thrombin generation was 400 nanomolar or less and found they have a recurrence risk of only seven per cent after four years. This represented two thirds of the 914 patients in the study. Those with a higher thrombin generation have a higher risk of recurrence and had something to gain from indefinite anticoagulants. This test could be used to identify those patients who do and do not need anticoagulant treatment to be continued.

Source
Journal of the American Medical Association 26th July 2006 Volume 296 pages 397-402