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);
Systolic blood pressure (SBP) < 90 mmHg or a drop ≥ 40 mmHg from baseline for > 15 minutes not attributable to arrhythmia, hypovolemia, or sepsis,
Requirement for vasopressors to maintain SBP ≥ 90 mmHg,
Cardiogenic shock, defined by clinical signs of end-organ hypoperfusion (e.g., altered mental status, oliguria, lactate elevation),
Need for ECMO or other mechanical circulatory support initiated prior to assessment,