The current guidelines from the American College of Chest Physicians (Kearon et al Chest 2012) and the Scientific Statement from AHA (Jaff et al Circulation 2011) favor 3-6 months of anticoagulation with no further treatment thereafter in unprovoked deep vein thrombosis/pulmonary embolism (DVT/PE), largely due to the risk of bleeding in the setting of prolonged warfarin therapy. Two studies have been published this year in NEJM that challenge this practice.
In the AMPLIFY-EXT study, Agnelli et al report that the use of apixaban, the oral factor Xa inhibitor, in patients with a history of DVT or PE for 12 months after 6-12 months of therapy with oral anticoagulants decreased the risk of recurrent DVT or PE or death compared to placebo. Two doses of apixaban were studied, both of which reduced the risk of DVT/PE/death from 11.6% with placebo to ~4%, depending on the dose of apixaban used (4.2% with 5 mg of apixaban or 3.8% with 2.5 mg of apixaban).
These results are similar to those observed in the WARFASA study published earlier this year and featured in an “Expert Is In” post here at CardioExchange. In that study, ASA 100mg was administered for 2 years after the discontinuation of anticoagulant therapy (and compared to placebo). DVT/PE recurred in 11.2% in those who received placebo over the 2-year period vs. 6.6% of the patients treated with ASA.
Taken together these articles reinforce the need for prolonged treatment in patients with unprovoked DVT/PE. More than 90% of the patients in the AMPLIFY-EXT study had unprovoked DVT/PE, and in the placebo group nearly 9% had a recurrent venous thromboembolism (VTE) or VTE-related death in the 12 months follow-up. With a 10% recurrence rate over the course of a year, DVT/PE should be managed as a lifelong condition, just the same way we manage ischemic heart disease.
- Are you planning to use apixaban or aspirin as extended treatment for your patients with DVT/PE??
- How long are you treating your patients with unprovoked DVT/PE?