Ultrasound-Assisted, Catheter-Directed Thrombolysis for Acute Intermediate/High Risk Pulmonary Embolism: Design of the Multicenter USAT IH-PE Registry and Preliminary Results

Catheter-based revascularization procedures developed as an alternative of systemic thrombolysis for patients at intermediate-high and high-risk pulmonary embolism. USAT IH-PE is a retrospective and prospective multicenter registry of such patients treated with ultrasound-facilitated, catheter-directed thrombolysis, whose preliminary results are presented in this study. The primary endpoint was the incidence of pulmonary hypertension (PH) at follow up. Secondary endpoints were short- and mid-term changes in echocardiographic parameters of right ventricle (RV) function, in-hospital and all-cause mortality, and procedure-related bleeding events. Between March 2018 and July 2023, 102 patients were included. The majority were at intermediate-high risk PE (86%), mostly female (57%), median age 66.5 years (IQR 56-74), and 28.4% had active cancer. Echocardiographic follow-up was available for 70 patients, and in only one the diagnosis of PH was confirmed by right heart catheterization, resulting in an incidence of 1.43% (CI 95%, 0.036-7.7). RV echocardiographic parameters improved both at 24 hours and at follow up. In-hospital mortality was 3.9% (CI 95%, 1.08-9.74) while all-cause mortality was 11% (CI 95%, 5.4-19.2). Only 12% had bleeding complications, oh whom 4.9% were BARC 3. Preliminary results from USAT IH-PE registry showed low incidence of PH, improvement in RV function and a safe profile.