Outcomes in High-Risk Pulmonary Embolism Patients Undergoing FlowTriever Mechanical Thrombectomy or Other Contemporary Therapies: Results From the FLAME Study

• Published in: Circulation. Cardiovascular interventions Vol. 16; no. 10; p. e013406
• Main Authors: Silver, Mitchell J., Gibson, C. Michael, Giri, Jay, Khandhar, Sameer, Jaber, Wissam, Toma, Catalin, Mina, Bushra, Bowers, Terry, Greenspon, Lee, Kado, Herman, Zlotnick, David M., Chakravarthy, Mithun, DuCoffe, Aaron R., Butros, Paul, Horowitz, James M.
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01.10.2023
• Subjects: Humans; Multicenter Studies as Topic; Observational Studies as Topic; Original; Prospective Studies; Pulmonary Embolism - etiology; Pulmonary Embolism - therapy; Thrombectomy - adverse effects; Thrombectomy - methods; Thrombolytic Therapy - adverse effects; Treatment Outcome; pulmonary embolism; thrombosis; anticoagulant
• ISSN: 1941-7640; 1941-7632; 1941-7632
• DOI: 10.1161/CIRCINTERVENTIONS.123.013406

Background: Hemodynamically unstable high-risk, or massive, pulmonary embolism (PE) has a reported in-hospital mortality of over 25%. Systemic thrombolysis is the guideline-recommended treatment despite limited evidence. The FLAME study (FlowTriever for Acute Massive PE) was designed to generate evidence for interventional treatments in high-risk PE. Methods: The FLAME study was a prospective, multicenter, nonrandomized, parallel group, observational study of high-risk PE. Eligible patients were treated with FlowTriever mechanical thrombectomy (FlowTriever Arm) or with other contemporary therapies (Context Arm). The primary end point was an in-hospital composite of all-cause mortality, bailout to an alternate thrombus removal strategy, clinical deterioration, and major bleeding. This was compared in the FlowTriever Arm to a prespecified performance goal derived from a contemporary systematic review and meta-analysis. Results: A total of 53 patients were enrolled in the FlowTriever Arm and 61 in the Context Arm. Context Arm patients were primarily treated with systemic thrombolysis (68.9%) or anticoagulation alone (23.0%). The primary end point was reached in 9/53 (17.0%) FlowTriever Arm patients, significantly lower than the 32.0% performance goal (P<0.01). The primary end point was reached in 39/61 (63.9%) Context Arm patients. In-hospital mortality occurred in 1/53 (1.9%) patients in the FlowTriever Arm and in 18/61 (29.5%) patients in the Context Arm. Conclusions: Among patients selected for mechanical thrombectomy with the FlowTriever System, a significantly lower associated rate of in-hospital adverse clinical outcomes was observed compared with a prespecified performance goal, primarily driven by low all-cause mortality of 1.9%. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04795167.