SOURCE: Couturaud F, et al. Six months vs extended oral anticoagulation after a first episode of pulmonary embolism: The PADIS-PE randomized clinical trial. JAMA 2015;314:31-40.

Utilization of anticoagulation in patients who have suffered an unprovoked pulmonary embolus (PE) is a complex issue. The most recent edition of the guidelines for antithrombotic therapy issued by the American College of Chest Physicians (AT9) suggests that after a minimum of 3 months’ anticoagulation post-PE, treatment decisions must be individualized based on bleeding risk. If bleeding risk is considered “low-moderate,” then indefinite anticoagulant therapy (with periodic reassessment) is suggested. But are there good outcomes data to support such a recommendation?

Couturaud et al performed a double-blind, placebo-controlled trial in 371 PE patients ascertaining risk of recurrent thromboembolism or major bleeding associated with extended anticoagulation. Patients who had already been treated with 6 months of warfarin were randomized to an additional 18 months of warfarin or placebo. Extended anticoagulation reduced recurrent thromboembolism by 85% (3 events vs 25 events). This benefit was counterbalanced by an increased incidence of major bleeding (4 patients in the warfarin group, 1 in the placebo group). There was no between-group difference in mortality.

After the initial 6-month treatment of PE, extended anticoagulation of up to 18 months dramatically reduces risk of recurrence at the expense of more episodes of major bleeding. Based on patient priorities and preferences, treatment will have to be individualized.