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

• Type of Material: Article
• Authors: Mitchell J. Silver, OhioHealth Heart and Vascular; C. Michael Gibson, Harvard University; Jay Giri, University of Pennsylvania; Sameer Khandhar, University of Pennsylvania; Wissam A. Jaber, Emory University; Catalin Toma, University of Pittsburgh; Bushra Mina, Lenox Hill Hospital; Terry Bowers, Corewell Health William Beaumont University Hospital; Lee Greenspon, Lankenau Medical Center; Herman Kado, Corewell Health William Beaumont University Hospital; David M. Zlotnick, Buffalo General Medical Center; Mithun Chakravarthy, AHn cardiovascular Institute at Allegheny General Hospital; Aaron R. DuCoffe, Fairfax Hospital; Paul Butros, Fairfax hospital; James M. Horowitz, New York University
• Language: English
• Date: 2023-10-17
• Publisher: American Heart Association
• Publication Version: Final Published Version
• Copyright Statement: © 2023 The Authors.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): https://doi.org/10.1161/CIRCINTERVENTIONS.123.013406
• Title of Journal or Parent Work: Circulation: Cardiovascular Interventions
• Volume: 16
• Issue: 10
• Start Page: e013406
• Grant/Funding Information: Inari Medical sponsored the FLAME study (FlowTriever for Acute Massive PE).
• Keywords: thrombosis; anticoagulant; pulmonary embolism
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

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%.