What is the role of thrombolysis with alteplase (tissue plasminogen activator) in managing acute pulmonary embolism, particularly in patients with hypotension?

From the Guidelines

Thrombolysis with alteplase (tPA) is recommended for patients with acute pulmonary embolism (PE) who present with hypotension or shock, as it can rapidly restore pulmonary perfusion and reduce right ventricular strain, thereby improving morbidity, mortality, and quality of life. The standard dosing regimen is 100 mg administered intravenously over 2 hours, as supported by the most recent guidelines 1. For patients at high bleeding risk, a reduced dose of 50 mg may be considered, although the optimal dosing strategy is not clearly defined due to a lack of comparative data between different approaches 1.

Key Considerations

• Thrombolysis should be initiated promptly in patients with hypotension (systolic BP < 90 mm Hg) and no high bleeding risk, as suggested by the latest Chest guideline and expert panel report 1.
• Before administration, clinicians should assess for contraindications including recent surgery, active bleeding, history of intracranial hemorrhage, or ischemic stroke within the past 3 months.
• Patients receiving thrombolysis require close monitoring for bleeding complications, with frequent vital sign checks and neurological assessments, as emphasized in the European Society of Cardiology guidelines 1.
• Hemodynamic support with fluids or vasopressors may be needed concurrently while the thrombolytic takes effect, particularly in patients with persistent arterial hypotension or cardiogenic shock 1.

Alternative Options

• For patients with contraindications to systemic thrombolysis, catheter-directed thrombolysis or surgical embolectomy may be alternative options to consider, as recommended by the European Society of Cardiology guidelines 1 and the Chest guideline and expert panel report 1.
• Selected patients with acute PE who deteriorate after starting anticoagulant therapy but have yet to develop hypotension and have an acceptable bleeding risk may also be considered for systemically administered thrombolytic therapy, as suggested by the latest Chest guideline and expert panel report 1.

From the Research

Thrombolysis in Acute Pulmonary Embolism

• Thrombolysis with alteplase (tissue plasminogen activator) is a treatment option for acute pulmonary embolism, particularly in patients with hypotension 2, 3.
• The use of thrombolytic agents in hemodynamically stable patients with right ventricular dysfunction is debated, with some studies suggesting that alteplase and heparin can reduce the risk of clinical deterioration requiring treatment escalation, but not reduce the risk of death 2, 4.
• In patients with submassive pulmonary embolism, alteplase and heparin have been shown to improve the clinical course and prevent clinical deterioration requiring treatment escalation during hospital stay 4.
• Risk stratification of patients with acute symptomatic pulmonary embolism is crucial to identify those who may benefit from thrombolysis, with patients presenting with arterial hypotension or shock having a high risk of death and being considered for thrombolysis 5.
• Alteplase has been shown to be effective and well-tolerated in patients with massive pulmonary embolism defined as the association of a pulmonary embolism with shock, with significant improvement in systolic and diastolic blood pressure and a low incidence of hemorrhagic events 3.

Patient Selection for Thrombolysis

• Patients with acute pulmonary embolism and hypotension or shock are considered high-risk and may benefit from thrombolysis 2, 5, 3.
• Normotensive patients with right ventricular dysfunction may also be considered for thrombolysis, although the evidence is less clear 2, 4.
• Risk stratification models, such as the Pulmonary Embolism Severity Index (PESI) and simplified PESI (sPESI), can help identify patients at low risk of dying shortly after diagnosis and those at higher risk of PE-related complications 5.

Administration and Monitoring of Alteplase

• Alteplase is typically administered as a bolus treatment over a period of 15 minutes 3.
• Nurses should monitor patients for signs of bleeding when alteplase is administered, as the risk of bleeding is a concern 6.
• Fibrinolytic therapy will frequently be started in the emergency department, and nurses must ensure that alteplase is administered in a safe and effective manner 6.