By Michael McDevitt, MD, PhD
About 2 million people in the United States are on long-term anticoagulation to treat thrombotic disease, which is a leading cause of death and disability. The diagnosis, prevention, and treatment of thrombosis remains a major component of most practicing hematologists’ consultative and clinical practice, as well as an active area for continued basic and clinical research. This topic is well represented at the 2008 ASH meeting. Yesterday, during the Education session on thrombosis, Dr. Henri Bounameaux, of the University Hospital of Geneva, Switzerland, spoke. In his talk, he covered the controversial issue of duration of oral anticoagulant treatment following an acute venous thromboembolic event. Dr. Bounameaux reviewed recently described guidelines recommending specific but variable treatment durations. His presentation described the dilemma of definite but individually variable risks of thromboembolic recurrence and bleeding secondary to anticoagulant treatment. Both the potential use of D-dimer measurement after an initial course of anticoagulant treatment to predict recurrence and a recently published bleeding risk score to predict bleeding will be considered. At the end of this extensive review, he provided his expert recommendations.
Dr. Charles Francis, of the University of Rochester Medical Center, was the second speaker of the session. As we all look forward to increased application of “personalized medicine,” Dr. Francis highlighted an early hematologic example. New information about warfarin pharmacogenetics that may lead to better dosing and improved outcomes was reviewed. He also covered new oral anticoagulants that may become alternatives to warfarin, which was introduced over 50 years ago. Dabigatran, rivaroxaban, and apixaban are either under regulatory review or in phase III clinical trials and show great promise. Their properties and results of recent clinical trials were discussed.
The final speaker of the session, Dr. Mark Crowther, of St. Joseph’s Hospital and McMaster University, in Hamilton, Ontario, Canada, discussed how best to reverse over-anticoagulation, a common problem leading to serious bleeding complications, with warfarin. Despite excellent clinical care, as many as 25 percent of INR determinations for patients on warfarin are above the reference interval, and approximately 10 percent are “dangerously elevated.” There is substantial evidence available now to guide the therapy of patients with warfarin-associated coagulopathy. Dr. Crowther used cases to identify treatment strategies for patients with this commonly seen clinical problem. Specific therapeutic recommendations were made for patients with or at risk of bleeding. Recent evidence supporting the use of vitamin K, fresh frozen plasma, and prothrombin complex concentrates was presented.
As a complement to these important practical presentations and the numerous oral presentations and abstracts referenced in the program guide, a special Symposium on the Basic Science of Hemostasis and Thrombosis has been organized for Tuesday, December 9, starting at 7:30 a.m. Co-chaired by Drs. Nigel Key, Eric Grabowski, and Elisabeth Cramer-Bordé, this session has been designed to expand the opportunity for exchange and communication among basic scientists in the field of hemostasis and thrombosis. It will highlight key important basic science contributions in 2008 in each of three major areas of the field: thrombosis, blood coagulation and fibrinolysis, and platelet biology. In addition to invited speakers presenting in the morning session, an afternoon session will include a number of oral presentations selected from abstracts submitted to ASH for the annual meeting. With presentations and sessions such as these, hopefully it won’t be long before our patients won’t need anticoagulation, or at least won’t need to have their INRs checked.
Dr. McDevitt indicated no relevant conflicts of interest.
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