Ultrasound-assisted, Catheter-directed Thrombolysis for Acute Intermediate-high-risk Pulmonary Embolism (USAT IH-PE): Impact on Short- and Long-term Outcome, a Multi-center Experience. An Observational Retrospective and Prospective Multi-center Study

Acute pulmonary embolism (PE) is a potentially life-threatening disease spanning a wide spectrum of clinical outcomes. PE is the third most common cardiovascular disorder in Europe and USA and causes an estimated 150,000 to 200,000 deaths.

In the latest 2019 European Society of Cardiology (ESC) Guidelines patients diagnosed with PE are stratified into different risk groups according to clinical history, hemodynamic status, cardiac biomarkers and imaging assessment of right ventricular (RV) function.

Traditionally, reperfusion therapy with systemic thrombolysis is the treatment of choice in high-risk PE, defined by sustained systemic arterial hypotension, cardiogenic shock, or the need for cardiopulmonary resuscitation.

In the setting of intermediate-risk PE,characterized by the absence of hemodynamic instability but elevated cardiac biomarkers or RV disfunction at imaging, the ESC guidelines recognize two sub-categories: intermediate-high if both signs are identified or intermediate-low, if only one of them is present.Approximately one quarter of hemodynamically stable patients with PE are at intermediate-risk, with mortality rates ranging from 3% to 15% if imaging or biomarker evidence of RV dilatation or dysfunction is present.4,5 In this subset of patients the optimal treatment strategy is still an object of debate.

A combination of ultrasound- based fragmentation of the thrombus and catheter-directed thrombolysis, requiring a reduced dose of the thrombolytic agent, has been developed. This localized therapy is currently recommended by the ESC guidelines (class IIa, LOE C) for patients with high-risk PE and contraindications for systemic thrombolysis or intermediate-high-risk PE and hemodynamic deterioration on anticoagulation treatment.