The duration of anticoagulation therapy for a provoked pulmonary embolism (PE) is generally recommended to be at least 3 months, with the possibility of extending the duration based on specific patient factors and risk profiles.
Initial treatment duration
- The American College of Chest Physicians (ACCP) 2016 guidelines recommend anticoagulant therapy for 3 months in patients with a proximal deep vein thrombosis (DVT) of the leg or PE provoked by surgery
- The European Society of Cardiology (ESC) 2019 guidelines recommend administering therapeutic anticoagulation for ≥ 3 months in all patients with PE, whether provoked or unprovoked
- The American Society of Hematology (ASH) 2020 guidelines suggest completing a shorter course (3–6 months) over a longer (6–12 months) course of anticoagulation for primary treatment of patients with DVT and/or PE, whether provoked by a transient risk factor, a chronic risk factor, or unprovoked
Considerations for extending therapy
- The ASH 2020 guidelines suggest offering indefinite antithrombotic therapy over stopping anticoagulation after completion of primary treatment in patients who develop DVT and/or PE provoked by a transient risk factor and have a history of previous unprovoked VTE or VTE provoked by a chronic risk factor
- The ASH 2023 guidelines suggest obtaining testing for thrombophilia to guide anticoagulant treatment duration after primary short-term treatment in patients with VTE provoked by a non-surgical major transient risk factor. Consider continuing anticoagulant treatment indefinitely in patients with thrombophilia and discontinuing it in patients without thrombophilia
Evidence from clinical trials
- A randomized trial found that for patients with DVT or PE and no known risk factors for recurrence, there seems to be little, if any, advantage in increasing the duration of anticoagulation from three to six months. Any possible benefit would need to be weighed against the increased risk of hemorrhage associated with the longer duration of treatment with warfarin
- Another study concluded that reducing the duration of anticoagulant therapy for venous thromboembolism provoked by a transient risk factor from 3 months to 1 month is likely to increase recurrent VTE without achieving a clinically important decrease in bleeding
In summary, the recommended duration of anticoagulation therapy for a provoked PE is generally at least 3 months. Extension of therapy beyond this period should be considered based on individual patient factors, risk of recurrence, bleeding risk, and guideline recommendations. Individualized assessment is crucial to determine the optimal duration of anticoagulation therapy for each patient.