Should I perform thrombolysis?

Thrombolysis in Pulmonary Embolism: Decision Algorithm

Thrombolysis is strongly recommended for patients with pulmonary embolism (PE) and hemodynamic compromise (high-risk/massive PE), but should not be routinely used for normotensive patients with submassive PE unless they show signs of clinical deterioration. 1

Patient Risk Stratification for Thrombolysis Decision

High-Risk PE (Massive PE)

• Hemodynamic compromise present:
  • Systolic BP <90 mmHg or drop ≥40 mmHg from baseline
  • Signs of shock or hypoperfusion
  • Action: Administer systemic thrombolysis followed by anticoagulation 1
  • Mortality benefit outweighs bleeding risk (mortality reduction of 20 fewer deaths per 1,000 cases) 1

Intermediate-Risk PE (Submassive PE)

• Normotensive with RV dysfunction:
  • Normal blood pressure (systolic BP ≥90 mmHg)
  • Evidence of RV dysfunction on imaging (echocardiography showing RV hypokinesis or RVSP >40 mmHg) 2
  • Elevated cardiac biomarkers (Troponin elevation, BNP >100 pg/mL, pro-BNP >900 pg/mL) 2
  • Action: Start anticoagulation alone and monitor closely 1

Deteriorating Intermediate-Risk PE

• Signs of clinical deterioration after starting anticoagulation:
  • Decrease in systolic BP
  • Increase in heart rate
  • Worsening gas exchange
  • Signs of inadequate tissue perfusion
  • Worsening RV function or increasing cardiac biomarkers 1, 2
  • Action: Consider thrombolysis if bleeding risk is acceptable 1

Bleeding Risk Assessment

Major bleeding risk increases significantly with thrombolysis (65 more events per 1,000 cases) 1, 2

Absolute contraindications to thrombolysis:

• Active internal bleeding
• Recent surgery, obstetrical delivery, biopsy, or puncture of non-compressible vessels (within 48 hours) 3
• Previous intracranial hemorrhage
• Intracranial malignancy
• Stroke within past 3 months

Relative contraindications:

• Thrombocytopenia or coagulopathy
• Severe hepatic or renal disease
• Pregnancy
• Current use of anticoagulants (especially with INR >1.7) 4

Thrombolysis Administration

If thrombolysis is indicated:

1. Systemic thrombolysis is preferred over catheter-directed thrombolysis for PE 1

   • Standard dose: Alteplase 100 mg IV over 2 hours 2

2. Consider catheter-directed thrombolysis in patients with:

   • High bleeding risk
   • Failed systemic thrombolysis
   • Shock likely to cause death before systemic thrombolysis can take effect 1
   • Requires appropriate expertise and resources

Special Considerations

Age

• Advanced age alone is not a contraindication to thrombolysis in high-risk PE
• For submassive PE, younger patients with low bleeding risk may be considered for thrombolysis 1

Catheter-Directed vs. Systemic Thrombolysis

• For PE, systemic thrombolysis is generally preferred over catheter-directed approaches 1
• Centers with appropriate infrastructure and experience may consider catheter-directed thrombolysis for patients with intermediate to high bleeding risk 1

Post-Thrombolysis Management

• Full anticoagulation should be continued after thrombolysis
• Avoid antiplatelet drugs in the first 24 hours after thrombolysis 4
• Monitor closely for bleeding complications, particularly intracranial hemorrhage

Key Pitfalls to Avoid

1. Delaying thrombolysis in patients with high-risk PE and hemodynamic compromise
2. Routine use of thrombolysis in all submassive PE patients (increased bleeding without clear mortality benefit)
3. Failure to monitor submassive PE patients for signs of deterioration
4. Overlooking contraindications to thrombolysis, especially recent surgery or trauma
5. Not considering catheter-directed approaches when systemic thrombolysis is contraindicated in high-risk PE

Remember that while thrombolysis can be life-saving in high-risk PE, the benefits and harms are finely balanced in submassive PE, with the risk-benefit ratio favoring thrombolysis primarily in patients who develop signs of clinical deterioration despite anticoagulation.