What is the treatment for pulmonary embolism?

Treatment for Pulmonary Embolism

The treatment of pulmonary embolism requires anticoagulation therapy with low molecular weight heparin (LMWH) as the initial treatment, followed by direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) for at least 3 months, with thrombolysis reserved only for massive PE with hemodynamic instability. 1

Initial Treatment Approach

Massive PE (with hemodynamic instability)

• Thrombolysis is first-line treatment 2
  • 50 mg bolus of alteplase recommended 2
  • May be instituted on clinical grounds alone if cardiac arrest is imminent 2
  • CTPA or echocardiography will reliably diagnose clinically massive PE 2
• Invasive approaches (thrombus fragmentation and IVC filter insertion) should be considered where facilities and expertise are available 2

Non-Massive PE

• Anticoagulation is the cornerstone of treatment
• Initial therapy options:

  1. Low Molecular Weight Heparin (LMWH) - preferred first-line option 1

     • Enoxaparin 1.0 mg/kg twice daily or 1.5 mg/kg once daily 1
     • Dalteparin 200 IU/kg once daily (max 18,000 IU) for first month, then 150 IU/kg once daily 1
     • More convenient than UFH with fixed dosing and no routine monitoring required 1

  2. Unfractionated Heparin (UFH) - consider in specific situations:

     • As first dose bolus 2
     • In massive PE 2
     • Where rapid reversal may be needed 2
     • In severe renal impairment (CrCl <30 mL/min) 1

Long-term Anticoagulation

After initial therapy, transition to one of the following:

Direct Oral Anticoagulants (DOACs)

• Preferred option for most patients due to fixed dosing, no routine monitoring, and fewer drug interactions 1
• FDA-approved options:
  • Rivaroxaban: 15 mg twice daily for 21 days, followed by 20 mg once daily 1, 3
  • Apixaban: 10 mg twice daily for 7 days, followed by 5 mg twice daily 1, 4
  • Dabigatran: 150 mg twice daily after initial LMWH 1
  • Edoxaban: 60 mg once daily (30 mg once daily if CrCl 30-50 mL/min or body weight <60 kg) 1

Vitamin K Antagonists (VKAs)

• Warfarin with target INR 2.0-3.0 2, 1
• Start at 5-10 mg (age-dependent) 1
• Continue parenteral anticoagulation for at least 5 days and until INR is 2.0-3.0 for two consecutive days 1
• Preferred for patients with antiphospholipid syndrome 1

Duration of Anticoagulation

Duration depends on clinical scenario:

• Temporary/reversible risk factors: 4-6 weeks to 3 months 2, 1
• First unprovoked PE: 3 months with consideration for extended therapy 2, 1
• Recurrent PE or persistent risk factors: At least 6 months to indefinite 2, 1

Special Populations

Cancer Patients

• LMWH is preferred for at least 6 months, followed by continuous anticoagulation while cancer is active 1

Pregnant Patients

• LMWH is the treatment of choice 1
• DOACs and VKAs are contraindicated 1

Renal Impairment

• For severe renal impairment (CrCl <30 mL/min), UFH followed by VKA is preferred 1

Follow-up Care

• Regular clinical follow-up at 3-6 months to assess:
  • Medication adherence
  • Bleeding complications
  • Signs of chronic thromboembolic pulmonary hypertension (CTEPH)
  • Need for extended anticoagulation 1

Outpatient Management

• Outpatient treatment with LMWH is safe and cost-effective for carefully selected patients who are hemodynamically stable with no need for thrombolysis 1
• Current organization for outpatient management of DVT should be extended to include stable patients with PE 2

Common Pitfalls to Avoid

1. Using thrombolysis in non-massive PE - Thrombolysis should not be used as first-line treatment in non-massive PE 2
2. Delaying imaging - Imaging should be performed within 1 hour in massive PE, and ideally within 24 hours in non-massive PE 2
3. Overlooking occult cancer - Consider investigations for occult cancer in idiopathic VTE when clinically suspected 2
4. Inappropriate DOAC use - Avoid DOACs in severe renal impairment, pregnancy, and antiphospholipid syndrome 1
5. Premature discontinuation - Ensure appropriate duration of anticoagulation based on risk factors to prevent recurrence 1