Should patients with chronic pulmonary embolism (PE) be anticoagulated with heparin (unfractionated heparin) upon admission?

From the Guidelines

Yes, patients with chronic pulmonary embolism (PE) should be anticoagulated upon admission.

Anticoagulation Recommendations

• The European Heart Journal recommends administering therapeutic anticoagulation for more than 3 months to all patients with PE 1.
• The Chest guideline suggests considering indefinite anticoagulation in patients with initial unprovoked PE, PE provoked by a persistent risk factor, and in patients with PE associated with a minor transient or reversible risk factor 1.

Initial Anticoagulation

• Unfractionated heparin is not the preferred initial anticoagulant, as the guidelines recommend low molecular weight heparin (LMWH) or vitamin K antagonists (VKAs) for long-term anticoagulation 1.
• The initial dose of anticoagulant should be adjusted to maintain a target INR of 2.5 (range 2.0-3.0) for VKAs 1.

Duration of Anticoagulation

• The duration of anticoagulant therapy should be at least 3 months for patients with PE secondary to a major transient/reversible risk factor 1.
• Indefinite anticoagulation is recommended for patients with recurrent unprovoked PE, PE and antiphospholipid antibody syndrome, and cancer patients with active disease 1.

From the FDA Drug Label

HEPARIN SODIUM INJECTION is an anticoagulant indicated for • Prophylaxis and treatment of venous thrombosis and pulmonary embolism

Yes, patients with chronic pulmonary embolism (PE) should be anticoagulated with heparin (unfractionated heparin) upon admission, as the drug label indicates that heparin is indicated for the treatment of pulmonary embolism 2.

From the Research

Anticoagulation Therapy for Chronic Pulmonary Embolism

• The use of anticoagulation therapy, specifically unfractionated heparin, in patients with chronic pulmonary embolism (PE) is a topic of discussion in various studies 3, 4, 5, 6.
• According to a study published in 2020, anticoagulation is performed with unfractionated heparin (UFH) in hemodynamically unstable patients, while low molecular weight heparins (LMWH) or fondaparinux are preferred in normotensive patients 3.
• Another study from 1998 suggests that therapy of pulmonary embolism should start with an intravenous bolus dose of 5000 U heparin followed by an infusion of 1250 U/h, and then the dose should be adjusted to maintain the aPTTX2-2.5 pre-treatment value 4.
• A study published in 2005 recommends a 5 to 7 day treatment with heparin followed by a treatment with oral anticoagulants given for at least 3 months for the majority of patients with pulmonary embolism 5.
• The goal of treatment of pulmonary embolism is the prevention of recurrent embolic events, achieved through conventional anticoagulant therapy with unfractionated heparin or a low molecular weight heparin, followed by warfarin therapy for a minimum of 6 months 6.

Patient-Specific Considerations

• The decision on the duration of anticoagulation should consider both the individual risk of PE recurrence and the individual risk of bleeding 3.
• Patients with a strong transient risk factor have a low risk of recurrence, and anticoagulation can be discontinued after three months, while patients with strong persistent risk factors have a high risk of recurrence and should receive anticoagulant treatment of indefinite duration 3.
• Special patient populations, such as breastfeeding mothers, those with end-stage renal disease, or obese patients, may require different anticoagulation management strategies 7.