Comparative outcomes of ultrasound-assisted thrombolysis and mechanical thrombectomy in intermediate–high-risk pulmonary embolism

Background Catheter-based reperfusion strategies, including ultrasound-assisted catheter-directed thrombolysis (USAT) and mechanical thrombectomy (MT), are increasingly used in intermediate-high-risk pulmonary embolism (PE), yet comparative real-world data remain limited. We compared short-outcomes, echocardiographic recovery, and mortality between USAT and MT. Methods We analysed 286 patients with acute intermediate–high risk PE enrolled in the multicentre USAT IH-PE registry (March 2018–October 2025). Patients underwent USAT (EKOS™, Boston Scientific) or MT (FlowTriever, Inari Medical; Indigo, Penumbra) during index hospitalisation. Primary endpoints were 30-day all-cause, cardiovascular, and PE-related mortality. Propensity score matching (1:1) balanced baseline characteristics. Kaplan–Meier analyses with log-rank testing assessed time-to-event outcomes. In-hospital bleeding was classified by BARC criteria. Changes in right ventricular (RV) function and pulmonary artery systolic pressure (PASP) were evaluated. Results After matching (69 patients per group), baseline clinical and hemodynamic variables were well balanced. Both USAT and MT significantly improved RV/LV ratio, tricuspid annular plane systolic excursion, and PASP (all p<0.001). Thirty-day all-cause mortality was similar between USAT and MT (13.0% vs. 11.5%; p=0.78), with no differences in cardiovascular or PE-related mortality. Survival curves did not differ at 30 days. Major bleeding was infrequent and observed only in the USAT group (4.3%, p=0.16). Conclusion In this real-world multicentre cohort, USAT and MT showed comparable short-term mortality, safety, and echocardiographic recovery, supporting individualized catheter-based reperfusion strategies for intermediate–high risk PE.