ULTRAsound-assisted Catheter-guided Thrombolysis for Intermediate-high Risk Patients With Pulmonary Embolism
Pulmonary embolism (PE) is a life-threatening condition and a leading cause of cardiovascular mortality. While systemic thrombolysis is the standard treatment for high-risk PE, its bleeding risk limits use in some patients, highlighting the need for alternative reperfusion strategies such as catheter-directed thrombolysis (CDT). This prospective study will evaluate the safety and efficacy of CDT using the EkoSonic Endovascular System (EKOS; Boston Scientific) in patients with intermediate-high and high-risk PE. The primary outcome is all-cause mortality through 360 days of follow-up, with secondary outcomes including changes in echocardiographic parameters such as the RV/LV diameter ratio.
• Adults aged ≥ 18 years at time of enrollment;
• Ability to provide written informed consent (or legally authorized representative consent where applicable);
• Objectively confirmed acute pulmonary embolism (PE) by contrast-enhanced computed tomography pulmonary angiography (CTPA) demonstrating intraluminal filling defects in at least one segmental, lobar, or more proximal pulmonary artery;
• Hemodynamically stable at presentation (i.e., not meeting high-risk PE criteria of sustained hypotension, shock, or need for vasopressor support per ESC 2019 and AHA/ACC risk stratification);
• Evidence of right ventricular (RV) dysfunction on imaging (e.g., RV/LV ratio \> 1.0 on CTPA or echocardiography);
• Elevated cardiac biomarkers, including troponin I or T above the upper limit of normal;
• Intermediate-high risk features defined as the combination of imaging RV dysfunction and positive cardiac biomarkers, consistent with ESC stratification;
• At least one clinical indicator of elevated early risk such as:
‣ Tachycardia (e.g., HR ≥ 100 bpm),
⁃ Mild systolic blood pressure reduction (e.g., SBP ≤ 110 mmHg but not meeting high-risk thresholds),
⁃ Hypoxemia (SpO₂ \< 90% on room air).