What Happens After 3 Months of PE Treatment
After completing 3 months of anticoagulation for PE, you must reassess the patient to determine whether to stop anticoagulation or continue indefinitely, based primarily on whether the PE was provoked or unprovoked, and secondarily on bleeding risk. 1
Decision Framework at 3 Months
Stop Anticoagulation After 3 Months
Discontinue anticoagulation in patients whose PE was provoked by a major transient/reversible risk factor (such as surgery, trauma, or temporary immobilization), as these patients have a low annual recurrence risk (<1%). 1
- For hormone-associated PE in women who have stopped estrogen therapy, anticoagulation beyond 3 months is not required, as these patients have approximately 50% lower recurrence risk compared to unprovoked PE. 1
- For isolated distal (calf) DVT without PE, even if unprovoked, anticoagulation beyond 3 months is generally not required due to lower recurrence risk. 1
Continue Anticoagulation Indefinitely
Continue anticoagulation indefinitely in patients with unprovoked PE or proximal DVT, as they have an annual recurrence risk exceeding 5%, which outweighs the bleeding risk of continued anticoagulation. 1
- Patients with recurrent VTE (at least one previous episode of PE or DVT) not related to a major transient risk factor must receive indefinite anticoagulation. 1
- Active cancer patients require indefinite anticoagulation due to persistently high recurrence risk. 1, 2
- Patients with antiphospholipid antibody syndrome must continue VKA (not NOAC) indefinitely. 1
Mandatory Follow-Up Actions
Clinical Re-evaluation at 3-6 Months
Routinely re-evaluate all PE patients at 3-6 months after the acute event to assess for chronic complications and determine ongoing anticoagulation needs. 1, 3
- Assess for persistent dyspnea, exercise intolerance, or signs of right heart dysfunction. 2
- Refer symptomatic patients with mismatched perfusion defects on V/Q scan beyond 3 months to a pulmonary hypertension/CTEPH expert center, incorporating echocardiography, natriuretic peptides, and/or cardiopulmonary exercise testing results. 1
For Patients on Extended Anticoagulation
Reassess drug tolerance, adherence, hepatic and renal function, and bleeding risk at regular intervals in all patients receiving extended anticoagulation. 1
- Monitor for any bleeding events, falls, or changes in bleeding risk factors. 1
- Verify continued absence of contraindications to anticoagulation. 1
Anticoagulation Regimen for Extended Treatment
For extended anticoagulation beyond 6 months, consider dose reduction to balance efficacy and bleeding risk:
- After at least 6 months of therapeutic anticoagulation with apixaban (5 mg twice daily), a reduced dose of 2.5 mg twice daily may be considered for extended prophylaxis. 4
- NOACs (apixaban, rivaroxaban, edoxaban, dabigatran) are preferred over VKA for extended treatment in eligible patients due to favorable safety profiles. 1, 5
Common Pitfalls to Avoid
- Do not routinely screen asymptomatic patients for CTEPH, but maintain high clinical suspicion in symptomatic patients. 2
- Do not use inferior vena cava filters routinely for extended VTE prevention. 1
- Do not use NOACs in patients with severe renal impairment (CrCl <25 mL/min) or antiphospholipid antibody syndrome—use VKA instead. 1
- Do not stop anticoagulation at 3 months in patients with unprovoked PE without carefully weighing their low bleeding risk, as recurrence rates are substantial (>5% annually). 1
Special Populations
For patients with non-surgical transient risk factors (e.g., medical illness, minor trauma), the recurrence risk falls between provoked-surgical and unprovoked PE—duration should be influenced by individual risk assessment, though long-term therapy is generally reserved for those without identifiable risk factors. 1
For women who wish to continue hormonal therapy after hormone-associated PE, continuation is acceptable only if combined with continued anticoagulation, as therapeutic anticoagulation likely suppresses any prothrombotic effect. 1