What is the treatment for pulmonary and cardiac thromboembolism?

Treatment of Pulmonary and Cardiac Thromboembolism

The treatment of pulmonary and cardiac thromboembolism requires immediate anticoagulation as the cornerstone therapy, with risk stratification guiding additional interventions such as thrombolysis or embolectomy for hemodynamically unstable patients. 1, 2

Risk Stratification

• Patients should be stratified based on hemodynamic stability to identify those at high risk of early mortality 2, 3
• High-risk PE: Patients with cardiogenic shock and/or persistent arterial hypotension 1, 2
• Intermediate-risk PE: Hemodynamically stable patients with evidence of right ventricular dysfunction 1, 2
• Low-risk PE: Hemodynamically stable patients without evidence of right ventricular dysfunction 1

Initial Management

High-Risk PE (with hemodynamic instability)

• Administer oxygen to correct hypoxemia 2, 3
• Initiate intravenous unfractionated heparin immediately with a loading dose of 5,000-10,000 units followed by 400-600 units/kg daily as continuous infusion 1
• Titrate heparin dose to maintain APTT at 1.5-2.5 times control values 1, 4
• Thrombolytic therapy is the first-line treatment for high-risk PE with very few absolute contraindications 1, 2
  • Streptokinase: 250,000 IU loading dose over 20-30 minutes, followed by 100,000 IU/hour for up to 24 hours 1
  • Recombinant tissue plasminogen activator (rtPA): 100 mg over 2 hours or bolus dose of 0.6 mg/kg over 15 minutes (maximum 50 mg) 1
• Consider surgical pulmonary embolectomy or catheter-directed treatment when thrombolysis is contraindicated or has failed 1, 3
• ECMO may be considered in combination with surgical embolectomy or catheter-directed treatment in refractory circulatory collapse or cardiac arrest 1

Intermediate and Low-Risk PE

• Initiate parenteral anticoagulation promptly 1, 2
• Low-molecular-weight heparin (LMWH) or fondaparinux is preferred over unfractionated heparin for hemodynamically stable patients 1, 5
• When oral anticoagulation is initiated, a non-vitamin K antagonist oral anticoagulant (NOAC) such as apixaban, dabigatran, edoxaban, or rivaroxaban is recommended over vitamin K antagonists (VKAs) 1, 5
• Thrombolysis may be considered in selected intermediate-risk patients with clinical deterioration 1, 2

Contraindications to Thrombolysis

Absolute Contraindications

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

Relative Contraindications

• Transient ischemic attack in preceding 6 months 1
• Oral anticoagulant therapy 1
• Pregnancy or within 1 week postpartum 1
• Non-compressible punctures 1
• Traumatic resuscitation 1
• Refractory hypertension (systolic blood pressure >180 mmHg) 1
• Advanced liver disease 1
• Infective endocarditis 1
• Active peptic ulcer 1

Surgical and Catheter-Based Interventions

• Surgical pulmonary embolectomy is indicated for patients with contraindications to or failure of thrombolysis 1
• Catheter embolectomy or fragmentation of proximal pulmonary arterial clots may be considered as an alternative to surgical treatment when thrombolysis is contraindicated or has failed 1
• Pulmonary thromboendarterectomy is the treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH) 1

Duration of Anticoagulation

• All patients should receive therapeutic anticoagulation for at least 3 months 1, 3
• For first PE secondary to a major transient risk factor (e.g., surgery), consider discontinuing anticoagulation after 3 months 3, 5
• Extended anticoagulation should be considered for patients with:
  • No identifiable risk factor for the index PE event 1
  • A persistent risk factor other than antiphospholipid antibody syndrome 1
  • A minor transient/reversible risk factor for the index PE event 1
• Indefinite treatment with a vitamin K antagonist is recommended for patients with antiphospholipid antibody syndrome 1
• A reduced dose of apixaban or rivaroxaban should be considered after the first 6 months for extended treatment 1

Follow-up Care

• Routine clinical evaluation is recommended 3-6 months after acute PE 1, 2
• Implement an integrated model of care to ensure optimal transition from hospital to ambulatory care 1, 2
• Refer symptomatic patients with mismatched perfusion defects on a V/Q scan >3 months after acute PE to a pulmonary hypertension/CTEPH expert center 1

Common Pitfalls to Avoid

• Do not delay anticoagulation while awaiting diagnostic confirmation in patients with intermediate or high clinical probability 3
• Do not routinely use systemic thrombolysis as primary treatment in patients with intermediate or low-risk PE 1, 3
• Do not routinely use inferior vena cava filters 3
• Do not use NOACs in patients with severe renal impairment or antiphospholipid antibody syndrome 3
• Do not discontinue anticoagulation prematurely in high-risk patients 1, 3