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

• DOI: 10.1161/circinterventions.123.013406
• Publication Date: 2023-10-17T18:01:34Z
• Authors: Mitchell J. Silver; C. Michael Gibson; Jay Giri; Sameer Khandhar; Wissam Jaber; Catalin Toma; Bushra Mina; Terry Bowers; Lee Greenspon; Herman Kado; David M. Zlotnick; Mithun Chakravarthy; Aaron R. DuCoffe; Paul Butros; James M. Horowitz
• Keywords: Observational Studies as Topic; Treatment Outcome; Humans; Multicenter Studies as Topic; Thrombolytic Therapy; Original Articles; Prospective Studies; Pulmonary Embolism; 3. Good health; Thrombectomy

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.