Large-bore Mechanical Thrombectomy in Intermediate-High and High-Risk Pulmonary Embolism: A Retrospective Single-Centre Case Series.

OBJECTIVES: To evaluate the clinical outcomes, efficacy, and safety of catheter-directed large-bore mechanical thrombectomy (LBMT) in patients with intermediate-high-risk and high-risk pulmonary embolism (PE). METHODS: This retrospective single-centre case series included 24 patients with acute PE treated with LBMT between August 2021 and November 2024 at Aarhus University Hospital, Denmark. Patients were classified into intermediate-high-risk and high-risk PE. Clinical data, imaging, procedural characteristics, and follow-up outcomes were collected. Primary outcomes included technical success, early clinical improvement, and changes in right ventricular (RV) function. Secondary outcomes comprised 30-day all-cause mortality, intensive care unit admission, procedural complications, and access site events. RESULTS: A total of 24 patients (8 intermediate-high-risk and 16 high-risk PE) were included of which 9 (38%) presented with cardiac arrest and 7 required veno-arterial extracorporeal membrane oxygenation support. LBMT was technically successful in all patients (100%) and early clinical improvement within 48 hours was observed in 71%. The RV/left ventricular ratio decreased after LBMT (from 1.8 ± 0.7 to 1.1 ± 0.4, p = 0.0002) and RV function improved. No device-related deaths or cardiac injuries occurred. Three patients (13%) died within 30 days, all of whom presented with cardiac arrest. CONCLUSIONS: LBMT was feasible and safe in a real-world cohort of intermediate-high-risk and high-risk PE patients, including those with PE-induced cardiac arrest or contraindications to thrombolysis. The procedure was associated with rapid clinical improvement and favourable hemodynamic outcomes, with a low rate of major complications. These findings support the use of LBMT as an alternative therapeutic option in selected PE patients.