Thrombolysis in Pulmonary Embolism

Risk Stratification and Treatment

The European Society of Cardiology recommends thrombolytic therapy for patients with high-risk pulmonary embolism presenting with cardiogenic shock and/or persistent arterial hypotension, but not for hemodynamically stable patients with intermediate or low-risk PE 1, 2
High-risk PE is characterized by hemodynamic instability with systolic hypotension or cardiogenic shock, and systemic thrombolytic therapy is recommended (Class I recommendation) unless absolute contraindications exist 1, 2, 3
Intermediate-risk PE is characterized by right ventricular dysfunction and/or myocardial injury but without hemodynamic instability, and routine use of thrombolysis is not recommended (Class III recommendation) 1, 2, 4
Low-risk PE patients are hemodynamically stable without evidence of right ventricular dysfunction or myocardial injury, and thrombolytic therapy should not be used (Class III recommendation) 1

For high-risk PE patients with contraindications to thrombolysis or in whom thrombolysis has failed, surgical pulmonary embolectomy is recommended (Class I recommendation) 1, 2
Percutaneous catheter-directed treatment should be considered (Class IIa recommendation) for high-risk PE patients with contraindications to thrombolysis or in whom thrombolysis has failed 1, 2

Absolute contraindications to thrombolysis include history of hemorrhagic stroke or stroke of unknown origin 4, ischemic stroke within previous 6 months 2, central nervous system neoplasm 2, major trauma, surgery, or head injury within previous 3 weeks 4, and active bleeding 4
Relative contraindications to thrombolysis include transient ischemic attack within previous 6 months 4, oral anticoagulation 2, pregnancy or first post-partum week 2, non-compressible puncture sites 2, traumatic resuscitation 2, and refractory hypertension 4

For complex cases, especially those with intermediate-high risk PE, involvement of a Pulmonary Embolism Response Team (PERT) is encouraged to enhance clinical decision-making through real-time multidisciplinary consultation 1

Initiate unfractionated heparin without delay in patients with high-risk PE 1, 2
Reserve thrombolysis primarily for high-risk PE with hemodynamic instability 1, 2
Consider surgical embolectomy or catheter-directed treatment when thrombolysis is contraindicated or has failed 1, 2

The American Heart Association recommends considering Inari FlowTriever mechanical thrombectomy primarily for hemodynamically unstable (high-risk) pulmonary embolism patients, particularly those with contraindications to thrombolysis or who have failed thrombolytic therapy, with a Class IIa recommendation 5, 6
Hemodynamically unstable PE is defined as sustained systolic blood pressure <90 mmHg for ≥15 minutes, requirement for inotropic support, pulselessness or persistent profound bradycardia, with a strong association with high mortality rates 6
The National Comprehensive Cancer Network suggests that rescue thrombectomy can be considered in hemodynamically stable intermediate-risk PE patients who experience clinical deterioration despite therapeutic anticoagulation, with a focus on right ventricular dysfunction and/or evidence of myocardial injury 6
Patients with right ventricular dysfunction, defined as elevated RV/LV ratio on imaging, and/or evidence of myocardial injury, defined as elevated cardiac biomarkers, may benefit from FlowTriever intervention, according to the European Society of Cardiology 5

The FlowTriever system is a large-bore (24F) aspiration device that mechanically removes thrombus without requiring adjunctive thrombolytics, with a high procedural success rate, as reported by the American College of Cardiology 5, 7, 8
The device uses self-expanding nitinol disks to engage thrombus and can function as a simple large-bore suction catheter, with a median procedure time of 52 minutes and fluoroscopy time of 13 minutes, as described by the Society for Cardiovascular Angiography and Interventions 7, 8

The European Respiratory Society recommends setting up multidisciplinary teams for management of high-risk and selected intermediate-risk PE cases, depending on available resources and expertise, with a focus on optimizing treatment selection and patient outcomes 9, 10
The FlowTriever system is FDA-cleared for use in acute PE and represents one of only two interventional devices with this specific clearance, as noted by the Food and Drug Administration 8