Do all pulmonary embolisms (PEs) require treatment?

From the Guidelines

Not all pulmonary embolisms (PEs) require treatment, as small, subsegmental PEs in patients with adequate cardiopulmonary reserve, no symptoms, and low risk of recurrence may be monitored without anticoagulation. The decision to treat is based on the PE's size, location, the patient's symptoms, risk factors, and overall clinical condition, as suggested by the 2020 ESC guidelines 1. According to these guidelines, treatment in the acute phase should involve systemic thrombolytic therapy for patients with high-risk PE, and surgical pulmonary embolectomy for patients with high-risk PE in whom recommended thrombolysis is contraindicated or has failed.

For patients without hemodynamic instability, the guidelines recommend preferring low molecular weight heparin (LMWH) or fondaparinux over unfractionated heparin (UFH) if anticoagulation is initiated parenterally 1. Some key points to consider when deciding on treatment include:

• The risk of recurrence and the patient's overall clinical condition
• The size and location of the PE
• The presence of symptoms and hemodynamic instability
• The patient's risk factors for bleeding and thrombosis

Initial treatment often involves low molecular weight heparin (such as enoxaparin 1mg/kg twice daily) or direct oral anticoagulants (DOACs) like apixaban (10mg twice daily for 7 days, then 5mg twice daily) or rivaroxaban (15mg twice daily for 21 days, then 20mg daily), as outlined in the 2008 ESC guidelines 1. Treatment duration is usually 3-6 months for provoked PEs and may be indefinite for unprovoked PEs. Severe PEs causing hemodynamic instability may require thrombolytic therapy (such as alteplase 100mg IV over 2 hours) or surgical thrombectomy. The 1997 British Thoracic Society study suggests that patients with suspected or even proven minor embolism and no evidence of residual DVT may not necessarily require treatment, particularly if risk factors are only temporary 1.

From the FDA Drug Label

1.4 Treatment of Pulmonary Embolism Apixaban tablets are indicated for the treatment of PE.

1.3 Treatment of Pulmonary Embolism XARELTO is indicated for the treatment of pulmonary embolism (PE).

Treatment of Pulmonary Embolism (PE) is indicated for both apixaban and rivaroxaban.

• The labels do not specify that all PEs require treatment, but rather that the medications are indicated for the treatment of PE.
• It can be inferred that treatment may be necessary for some, but not necessarily all, PEs, depending on the specific clinical context and patient factors.
• However, without further information, no conclusion can be drawn about which specific PEs may not require treatment 2 3 3.

From the Research

Treatment of Pulmonary Embolisms (PEs)

Not all PEs require the same level of treatment, as the approach depends on the patient's risk stratification and clinical presentation.

• Patients with a low probability of PE (less than 15%) and certain clinical characteristics may not require further testing 4.
• Those with a high probability of PE (more than 40%) should undergo chest imaging, and D-dimer testing is not necessary 4.
• The initial treatment for PE typically involves anticoagulants with rapid onset of action, either parenteral (heparin/fondaparinux) or oral (direct oral anticoagulants, DOACs) 5.
• Patients with PE and a systolic blood pressure of 90 mm Hg or higher can be treated with direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, which have a lower rate of bleeding compared to heparin combined with a vitamin K antagonist 4.
• Systemic thrombolysis is recommended for patients with PE and systolic blood pressure lower than 90 mm Hg, as it is associated with a reduction in mortality 4.

Risk Stratification and Treatment

The risk stratification of patients with PE is crucial in deciding the best management and treatment strategy.

• Low-risk patients may be eligible for home therapy, while those at intermediate risk require hospitalization and possibly more intensive monitoring 5.
• The treatment approach may vary depending on the patient's clinical presentation, age, and other factors, such as the presence of active cancer or frailty 6.
• The use of DOACs, such as rivaroxaban and apixaban, has been shown to be effective and safe for the treatment of PE, with a lower risk of bleeding compared to traditional anticoagulants 6, 7.
• The duration of anticoagulant therapy should be individualized based on the patient's risk-to-benefit ratio, taking into account factors such as the type of index event, age, and sex 5, 7.