What are the indications for thrombolysis in pulmonary embolism (Pulmonary Embolism)?

From the Guidelines

Thrombolysis is recommended for patients with high-risk pulmonary embolism (PE), as it leads to faster improvements in pulmonary obstruction, pulmonary artery pressure (PAP), and pulmonary vascular resistance (PVR), accompanied by a reduction in right ventricular (RV) dilation on echocardiography 1.

Indications for Thrombolysis

The indications for thrombolysis in pulmonary embolism include:

• High-risk PE, characterized by hemodynamic instability with systolic blood pressure <90 mmHg or a drop of ≥40 mmHg for >15 minutes not caused by arrhythmia, hypovolemia, or sepsis
• Selected intermediate-risk (submassive) PE patients who have right ventricular dysfunction on echocardiography or CT, elevated cardiac biomarkers (troponin, BNP), and a low bleeding risk

Thrombolytic Regimen

The standard thrombolytic regimen is:

• Alteplase (tPA) 100 mg IV over 2 hours
• Accelerated protocols exist, including 50 mg over 15 minutes in critically ill patients
• Alternative agents include reteplase (10 units IV twice, 30 minutes apart) or tenecteplase (single weight-based bolus)

Contraindications

Absolute contraindications for thrombolysis include:

• Active internal bleeding
• Recent stroke
• Intracranial neoplasm
• Major surgery/trauma within 3 weeks

Monitoring and Complications

Patients require close monitoring in an ICU setting during and after administration, with frequent vital sign checks and assessment for bleeding complications, as thrombolysis can lead to severe bleeding and intracranial hemorrhage 1.

Benefits of Thrombolysis

Thrombolysis has been shown to reduce the combined outcome of mortality and recurrent PE, with a significant reduction in PE-related and overall mortality of as much as 50-60% following thrombolytic treatment in the intermediate-risk category 1.

From the FDA Drug Label

Kinlytic™ is indicated in adults: For the lysis of acute massive pulmonary emboli, defined as obstruction of blood flow to a lobe or multiple segments. For the lysis of pulmonary emboli accompanied by unstable hemodynamics, i.e., failure to maintain blood pressure without supportive measures. The indications for thrombolysis in pulmonary embolism are:

• Acute massive pulmonary emboli: defined as obstruction of blood flow to a lobe or multiple segments
• Pulmonary emboli with unstable hemodynamics: failure to maintain blood pressure without supportive measures 2

From the Research

Indications for Thrombolysis in Pulmonary Embolism

The indications for thrombolysis in pulmonary embolism (PE) are based on the risk stratification of patients, which includes high-risk and intermediate-risk PE.

• High-risk PE is characterized by the presence of cardiogenic shock and/or persistent arterial hypotension, and thrombolysis is the mainstay of therapy in these patients 3, 4, 5.
• Intermediate-risk PE, also known as submassive PE, is characterized by right ventricular dysfunction or injury, but without hypotension, and thrombolysis may be considered on a case-by-case basis, taking into account bleeding risk, cardiac biomarkers, echocardiography, and clinical status 4, 6, 5.

Patient Selection for Thrombolysis

Patient selection for thrombolysis is crucial to minimize the risk of bleeding complications.

• Patients with high-risk PE should receive thrombolytic therapy unless severe contraindications are present 3, 4, 5.
• Patients with intermediate-risk PE should be considered for thrombolysis if they are 75 years or less of age and are at low risk of bleeding, and if they have right ventricular dysfunction or injury, as evidenced by echocardiography or cardiac biomarkers 4, 6.

Special Considerations

There are special considerations for thrombolysis in certain situations, such as during cardiopulmonary resuscitation (CPR).

• Thrombolysis during CPR may be considered in patients with massive pulmonary embolism or acute myocardial infarction, after conventional CPR procedures have been performed unsuccessfully 7.