Balancing the risks of blood thinners
A world-first research study led by Dr. Marc Rodger has identified a simple rule that may allow hundreds of thousands of women to stop taking blood thinning pills such as warfarin. The study examined 646 people with unexplained blood clots in the legs, arms and lungs (called unprovoked venous thromboembolism). These clots affect up to 2.5 per cent of people in their lifetime and are a major cause of death. Once the initial blood clot is treated, warfarin is prescribed to reduce the risk of further clotting. Currently, many patients take warfarin for the rest of their lives, despite the fact that drug has serious side effects, such as increased risk of bleeding. Dr. Rodger’s study is the first to identify a group of patients (women with four clinical characteristics) who had a very low risk of blood clot recurrence and therefore may be able to safely stop taking warfarin after six months. If the results are confirmed in further studies and this rule becomes widely used, it could help prevent many cases of major bleeding and death and also reduce the large health care costs associated with chronic warfarin therapy. The study was funded by the Canadian Institutes of Health Research and published in the Canadian Medical Association Journal.