As primary care clinicians, we rarely stand at the bedside in the emergency department or the intensive care unit during the acute crisis of a pulmonary embolism (PE). However, once the initial storm settles and the patient is discharged, they return to our clinics. That is where our real work begins. Managing long-term anticoagulation, monitoring for chronic complications, and deciding exactly when it is safe to stop treatment are tasks that fall squarely on our shoulders.
To help us with this, the American Heart Association (AHA) and the American College of Cardiology (ACC), along with a broad coalition of specialties, released updated guidelines for evaluating and managing acute pulmonary embolism in adults.
For years, the medical community relied on terms like "massive," "sub-massive," and "low-risk" to classify PE severity. The updated guidelines completely retire this terminology, introducing a nuanced clinical classification scheme spanning five categories (A through E). This schema ranks severity based on clinical presentation, symptom load, and cardiopulmonary risk factors, from category A (subclinical) to category E (cardiopulmonary failure).
When transitioning a patient to outpatient care, selecting or maintaining the appropriate anticoagulant is critical. The clinical evidence is clear: direct oral anticoagulants (DOACs) are strongly recommended over vitamin K antagonists (VKAs), such as warfarin, for most patients.
Multiple high-quality trials demonstrate that DOACs are non-inferior or superior to warfarin in preventing recurrent venous thromboembolism (VTE), while carrying a significantly lower risk of major bleeding complications. However, there are a few notable populations where DOACs are either contraindicated or less effective than traditional therapies:
Antiphospholipid Syndrome (APLS): Patients with confirmed APLS require traditional vitamin K antagonists (warfarin) rather than DOACs, as DOACs carry a higher rate of recurrent thrombosis in this specific cohort.
Severe Hepatic Dysfunction: For patients with advanced liver disease classified as Child-Pugh Class C, VKAs remain the recommended approach over DOACs.
Pregnancy and Breastfeeding: DOACs cross the placenta and enter breast milk. Pregnant patients must be managed with low-molecular-weight heparin (LMWH). Breastfeeding patients should receive either LMWH or standard VKAs.
Determining exactly how long a patient needs to remain on a blood thinner can cause significant clinical anxiety. The guidelines simplify this decision by anchoring therapy duration directly to the risk factors present during the initial thrombotic event. Risk factors fall into three categories: major reversible, persistent, and minor reversible.
|
Risk Factor Category |
Clinical Scenario |
Recommended Treatment Duration |
|---|---|---|
|
Major Reversible |
Surgery with general anesthesia (>30 mins), medical hospitalization (>72 hours) with bed confinement, Cesarean section, lower limb fracture |
3 to 6 months (Class 1 Indication) |
|
Persistent |
Active malignancy, systemic autoimmune disease, inflammatory bowel disease (IBD), chronic immobility |
Indefinite (Class 1 Indication) |
|
Minor Reversible |
Surgery (<30 mins), brief hospitalization (<72 hours), estrogen therapy, peripartum period, minor trauma with immobility (>72 hours) |
Individualized weigh VTE recurrence vs. bleeding risk (Class 2a Indication) |
|
No Known |
Indefinite (Class 1 indication) |
When a patient experiences a PE with no identifiable major or minor reversible or persistent risk factors, they require indefinite anticoagulation beyond the initial 3-to-6-month period (Class I indication). Data indicates that 30% to 40% of these patients experience a recurrent VTE within 10 years of stopping treatment.
Reframing this concept for patients is highly valuable. Rather than telling them they have "no risk factors," explain that they likely have an "unknown" risk factor. Clinicians can share this comforting script:
"We might not know exactly why this blood clot happened, but that doesn't mean it happened for no reason. Because the cause is hidden, we know your risk of developing another clot in the future is remarkably high. Unless we develop a compelling reason to stop, keeping you safely on this medication is our best defense."
Indefinite doesn’t always mean forever! Primary care clinicians should feel fully empowered to re-evaluate long-term treatment plans. As the longitudinal provider, you must periodically review the clinical picture. A patient's bleeding risk, renal/hepatic function, and personal preferences change over time. Even persistent risk factors can resolve, such as a patient entering complete, long-term cancer remission. If the risk-benefit equation shifts, it is entirely appropriate to discuss stopping therapy.
A frequent misconception in clinical practice is that once a clot dissolves, the pulmonary vasculature returns to a pristine state. In reality, the profound inflammation and mechanical structural damage caused by an acute PE can leave long-term vascular scars.
Up to 50% of patients continue to experience dyspnea or physical limitations three months after a PE. Primary care providers are uniquely positioned to catch these long-term complications early, a condition known as Chronic Thromboembolic Pulmonary Disease (CTEPD).
It is critical to distinguish between CTEPD and chronic thromboembolic pulmonary hypertension (CTEPH), two related but distinct conditions:
CTEPD: This term describes a broad clinical spectrum. It encompasses patients who have had a confirmed PE and continue to experience persistent dyspnea, exercise limitations, or residual pulmonary vascular occlusion, with or without resting pulmonary hypertension.
CTEPH: This is a specific, severe subset within the CTEPD spectrum. Patients with CTEPH have both chronic thromboembolic disease and confirmed resting pulmonary hypertension.
The guidelines issue a Class 1 recommendation that all patients should be actively screened for PE-related symptoms and functional limitations at every visit for at least one full year following an acute event. Because symptoms like fatigue and shortness of breath overlap heavily with deconditioning, asthma, or mood disorders, diagnoses are frequently delayed. If a patient continues to struggle with exertion post-PE, initiate a diagnostic workup consisting of a transthoracic echocardiogram (TTE) and a ventilation-perfusion (V/Q) scan, supplemented by cardiopulmonary exercise testing if indicated.
Key Clinical Takeaways for Primary Care
Prioritize DOACs: Use DOACs as the preferred first-line standard over warfarin, being mindful of specific exceptions like pregnancy, breastfeeding, severe liver failure, and triple-positive APLS.
Clarify the Duration Strategy: Use the risk-factor framework to guide the duration of therapy. Treat unprovoked PEs as having "unknown" risks requiring indefinite treatment, but regularly re-assess that choice as the patient ages.
Actively screen for CTEPD: Ask about dyspnea and functional limitations at every visit for at least a full year post-PE to catch chronic thromboembolic disease before significant long-term disability sets in.
You can hear more on this topic on the September 2026 episode of Primary Care RAP! Check out a clip from the episode below!
References:
Creager MA, Barnes GD, Giri J, et al. 2026 AHA/ACC/ACCP/ACEP/CHEST/SCAI/SHM/SIR/SVM/SVN guideline for the evaluation and management of acute pulmonary embolism in adults: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2025. doi:10.1016/j.jacc.2025.11.005