What is the recommended treatment for pulmonary embolism?

Treatment of Pulmonary Embolism

Initiate anticoagulation immediately with a direct oral anticoagulant (DOAC)—specifically rivaroxaban or apixaban—as first-line therapy for most patients with confirmed pulmonary embolism, as these single-drug regimens are now preferred over warfarin and low-molecular-weight heparin combinations. 1

Risk Stratification Determines Treatment Intensity

Risk stratification based on hemodynamic stability is the critical first step that determines treatment intensity 2:

High-Risk PE (Hemodynamically Unstable):

• Defined by systolic blood pressure <90 mmHg, need for vasopressors, or cardiogenic shock 1, 2
• Immediately administer unfractionated heparin (UFH) intravenously without waiting for diagnostic confirmation: initial bolus of 80 U/kg IV followed by continuous infusion of 18 U/kg/h, adjusted based on aPTT to maintain 1.5-2.5 times control value (46-70 seconds) 1, 3
• Systemic thrombolytic therapy is mandatory unless absolute contraindications exist 1, 2
• Consider surgical pulmonary embolectomy if thrombolysis is contraindicated or fails 2
• Percutaneous catheter-directed treatment should be considered as an alternative 2
• Use norepinephrine and/or dobutamine for hemodynamic support 2

Intermediate-Risk and Low-Risk PE (Hemodynamically Stable):

• Intermediate-risk: hemodynamically stable but with right ventricular dysfunction on imaging or elevated cardiac biomarkers 1, 2
• Low-risk: hemodynamically stable without RV dysfunction or myocardial injury 1, 2
• Both categories should receive DOAC therapy as first-line treatment 1, 2

Anticoagulation Strategy for Stable Patients

Direct Oral Anticoagulants (DOACs) - First-Line:

Rivaroxaban (FDA-approved for PE treatment) 4:

• 15 mg orally twice daily for 3 weeks, then 20 mg once daily 3
• Can be initiated immediately without parenteral lead-in 1
• Take with food for optimal absorption 4

Apixaban (FDA-approved for PE treatment) 5:

• Higher dose during the first week, then maintenance dosing 3
• Can be initiated immediately without parenteral lead-in 1
• Effective alternative in cancer patients 3

Dabigatran:

• Requires at least 5-10 days of parenteral anticoagulation (LMWH or fondaparinux) before initiation 3
• Non-inferior to warfarin with fewer bleeding episodes 3

Alternative Anticoagulation (When DOACs Not Suitable):

For patients who cannot receive DOACs, use LMWH or fondaparinux followed by warfarin 1:

• Continue parenteral anticoagulation until INR reaches 2.5 (range 2.0-3.0) for 2 consecutive days 2, 3
• Never stop parenteral anticoagulation before achieving therapeutic INR for 2 consecutive days 1, 3

Special Populations

Cancer Patients:

• LMWH is the preferred initial and long-term treatment 1, 3
• Dalteparin dosing: 200 IU/kg once daily for 1 month, then 150 IU/kg once daily for 5 months 3
• Apixaban is an effective alternative 3

Pregnant Patients:

• Use therapeutic fixed doses of LMWH based on early pregnancy weight 1, 2
• All pregnant women with suspected or confirmed PE should be reviewed by a consultant and discussed with maternity services prior to discharge 1
• DOACs are contraindicated in pregnancy 2

Severe Renal Impairment (CrCl <30 mL/min):

• UFH is preferred 3
• DOACs are contraindicated in severe renal impairment 2

Antiphospholipid Syndrome:

• Continue vitamin K antagonist (warfarin) indefinitely 1, 2
• DOACs are contraindicated 2

Duration of Anticoagulation

Provoked PE (secondary to major transient/reversible risk factor):

• Discontinue anticoagulation after 3 months 1, 2

Unprovoked PE or Recurrent VTE:

• Continue anticoagulation indefinitely 1, 2

Antiphospholipid Antibody Syndrome:

• Indefinite anticoagulation with a vitamin K antagonist is mandatory 1, 2

All patients require therapeutic anticoagulation for a minimum of 3 months 2

Inferior Vena Cava Filters

• Avoid routine use of IVC filters 1, 2
• Consider only for absolute contraindications to anticoagulation or recurrent PE despite therapeutic anticoagulation 1, 2

Critical Pitfalls to Avoid

Never delay anticoagulation while awaiting diagnostic confirmation in patients with high or intermediate clinical probability 1, 3

Avoid aggressive fluid resuscitation in high-risk PE, as it can worsen right ventricular failure 1, 3

Never prematurely discontinue anticoagulation without considering coverage with another anticoagulant, as this increases the risk of thrombotic events 4

Monitor for spinal/epidural hematomas in patients receiving neuraxial anesthesia or undergoing spinal puncture while on anticoagulation 4

Follow-Up

• Carefully selected low-risk PE patients should be considered for early discharge and home treatment 2
• Routinely re-evaluate all patients 3-6 months after acute PE to assess for chronic thromboembolic pulmonary hypertension and persistent symptoms 2