Comparison of ultrasound-assisted thrombolysis and mechanical thrombectomy in intermediate-high-risk pulmonary embolism.

Background: Pulmonary embolism (PE) can result in high mortality. Early risk stratification and treatment are critical for individualized management. In patients with intermediate-high-risk (IHR) PE, guidelines recommend to consider a percutaneous catheter-directed treatment (CDT). While different techniques are available, comparisons between treatments regarding right ventricular (RV) function and outcome are still scarce. This study aimed to compare changes in RV function as well as outcomes in patients with IHR PE after CDT with ultrasound-assisted thrombolysis (USAT) as compared to large-bore mechanical thrombectomy (MT). Patients and methods: This is a retrospective, single-center study in IHR PE, diagnosed in accordance with the ESC Guidelines. All patients underwent a CDT either with USAT (EKOS, Boston Scientific) or MT (FlowTriever System, Inari). Right heart function (RV/LV ratio, TAPSE) was assessed via transthoracic echocardiography before and after CDT as well as interventional characteristics and postinterventional hospital stay were compared. Results: From June 2022 to April 2024, 26 patients (35% female; aged 61.2±15.2 years) were diagnosed with IHR PE and underwent CDT. 14 patients (53.8%) were treated with USAT and 12 patients (46.2%) with MT. The mean procedural time was 40.4±19.8 minutes for USAT and 104±32.2 minutes for MT. RV/LV ratio was improved in both groups (change from baseline USAT -0.48±0.25; MT -0.36±0.13). TAPSE increased by 6.95±3.7 mm in USAT and by 9.8±4.6 mm in MT. Major bleeding (defined as BARC ≥ 3a) occurred only in three patients of the USAT group. The 90-day mortality rate was 0% in both groups. Conclusions: In patients with IHR PE both USAT and MT lead to an improved RV function without mortality within 90 days. Further randomized data have to discriminate the differential impact of novel tools for the treatment of IHR PE.