What is the treatment for high-risk pulmonary embolism (PE) with severe right ventricular dysfunction or hypotension?

Treatment of High-Risk Pulmonary Embolism

Systemic thrombolytic therapy is the first-line treatment for patients with high-risk pulmonary embolism (PE) presenting with cardiogenic shock and/or persistent arterial hypotension, with very few absolute contraindications. 1

Initial Assessment and Management

• High-risk PE is characterized by:

  • Hypotension (systolic BP <90 mmHg)
  • Collapse
  • Unexplained hypoxia
  • Engorged neck veins
  • Right ventricular gallop (often) 1

• Immediate actions for high-risk PE:

  • Oxygen supplementation
  • Hemodynamic support
  • Contact consultant immediately 1
  • Administer 80 units/kg heparin IV bolus 1

Thrombolytic Therapy

• For high-risk PE with hypotension:

  • Administer 50 mg alteplase IV in deteriorating patients 1
  • For stable confirmed massive PE: 100 mg alteplase over 90 minutes (accelerated regimen) 1
  • Alternative regimens:
    • rtPA: 100 mg over 2 hours or 0.6 mg/kg over 15 minutes (maximum 50 mg) 1
    • Short infusion times (2 hours) are preferred over prolonged infusions (24 hours) 1
    • Administration through peripheral vein is preferred over pulmonary artery catheter 1

• Follow thrombolysis with unfractionated heparin after 3 hours, preferably weight-adjusted 1

Alternatives When Thrombolysis is Contraindicated

• Surgical pulmonary embolectomy is indicated when:

  • Thrombolysis is contraindicated
  • Thrombolysis has failed
  • Shock is likely to cause death before thrombolysis can take effect 1

• Catheter-assisted thrombus removal should be considered when:

  • Thrombolysis is contraindicated
  • Thrombolysis has failed
  • Shock is likely to cause death before systemic thrombolysis can take effect 1

• Urgent transfer to a center with capability for catheter-directed intervention is recommended if thrombolysis is contraindicated 2

Anticoagulation Therapy

• For patients with high-risk PE:

  • Initial anticoagulation with unfractionated heparin (UFH) is preferred over LMWH or fondaparinux due to:
    • Concerns about subcutaneous absorption
    • Potential need for thrombolytic therapy
    • Ability to rapidly reverse effect if needed 1, 2

• UFH dosing and monitoring:

  • Initial bolus: 80 U/kg
  • Continuous infusion: 18 U/kg/hour
  • Target aPTT ratio: 1.5-2.5 times control value
  • First aPTT should be measured 4-6 hours after starting therapy 2

• After stabilization, transition to oral anticoagulation:

  • Direct oral anticoagulants (DOACs) are preferred for eligible patients
  • For apixaban: 10 mg twice daily for 7 days, then 5 mg twice daily 2, 3

Contraindications to Thrombolytic Therapy

• Absolute contraindications:

  • Hemorrhagic stroke or stroke of unknown origin at any time
  • Ischemic stroke in preceding 6 months
  • Central nervous system damage or neoplasms
  • Recent major trauma/surgery/head injury (within preceding 3 weeks)
  • Gastrointestinal bleeding within the last month
  • Known bleeding 1

• Note: Contraindications that are considered absolute in other conditions (e.g., acute myocardial infarction) might become relative in immediately life-threatening high-risk PE 1

Special Considerations

• Patients with out-of-hospital cardiac arrest due to PE rarely recover 1
• Norepinephrine, isoproterenol, and epinephrine are the pressor agents of choice for hypotension 4
• Avoid fluid challenges in hypotensive patients with right ventricular overload; hypotension may be relieved by preload reduction or gentle diuresis 4
• Standard closed-chest cardiopulmonary resuscitation may be ineffective when pulmonary circulation is obstructed by thrombus 4

By following this evidence-based approach to high-risk PE management, clinicians can significantly reduce mortality and morbidity in this life-threatening condition.