Standard vs Ultrasound-assisted Catheter Thrombolysis for Submassive Pulmonary Embolism

Acute pulmonary embolism (PE) accounts for 5-10% of in-hospital deaths. Systemic anticoagulation (AC) is the standard of care and thrombolysis is recommended for those at a higher mortality risk. Catheter-directed therapies, mainly standard catheter-directed thrombolysis (CDT) and ultrasound-accelerated thrombolysis (USAT), have been introduced as new, more effective, and safer treatment modalities. USAT is a modification of standard catheter thrombolysis, utilizing a system of local ultrasound to dissociate the fibrin matrix of the thrombus, allowing deeper penetration of lytics. However, there is limited data comparing the two treatments. More rapid clearance of pulmonary thrombus by USAT compared to standard CDT may prove to be more effective regarding clinical outcomes and cost (e.g. via reduced length of ICU and hospital stay). Alternatively, if thrombus clearance is similar, the cost of USAT may exceed the cost of CDT (equipment and disposables), without offering any potential advantage. This controlled, randomized study seeks to determine if ultrasound acceleration adds any benefits in the outcomes and costs of catheter-directed thrombolysis for patients with acute submassive PE. The treatment with CDT or USAT are standard of care for submassive PE and participants will be randomized to receive one treatment or the other. Participants will have follow up visits at 3 months and 12 months post procedure. All the procedures, tests, and follow up visits are according to current standard of care.