ACC 2023: Large bore mechanical thrombectomy reduces adverse outcomes in high-risk PE patients

Large bore mechanical thrombectomy with the FlowTriever system (Inari Medical) in patients with high-risk pulmonary embolism (PE) was associated with a significantly lower occurrence of meaningful in-hospital adverse clinical outcomes compared to other contemporary treatments, data presented at the American College of Cardiology (ACC) 2023 Scientific Sessions (4–6 March, New Orleans, USA) indicate.  

These were among the results of the FLAME study, a prospective, non-randomised study of interventional treatment in high-risk PE, a patient population with a historical mortality rate of 25–50%, which were presented at ACC 2023 by Mitchell Silver (OhioHealth Heart and Vascular, Columbus, USA).  

The study collected data on patients treated with the FlowTriever and on those treated with other therapies in a context arm. The primary endpoint measured a composite of meaningful in-hospital clinical outcomes, including mortality, major bleeding, clinical deterioration, and escalation to an alternate therapy.  

Silver reported that FLAME was stopped early after meeting the pre-specified interim analysis criterion at 50 FlowTriever patients. Sharing the results of the study, Silver noted that the endpoint was met in the FlowTriever arm, in which a mortality rate of 1.9% was recorded, compared to 29.5% in the context arm. In all, the composite primary endpoint occurred in 17% of patients in the FlowTriever arm, compared to 63.9% in the context arm. 

“The remarkably low mortality seen with FlowTriever demonstrates the benefit of rapidly identifying PE patients and getting them to an interventionalist for assessment,” Silver was quoted as saying in a press release issued shortly after the presentation of the results at ACC 2023. “It is time for our hospital systems to develop standardized care pathways for PE, similar to what has been done in other major cardiovascular diseases such as heart attack and stroke.” 

“High-risk PE persists as one of the deadliest cardiovascular diseases,” James Horowitz (NYU Grossman School of Medicine, New York, USA), FLAME national principal investigator was also quoted in the same release. “Outcomes have remained unchanged for decades. The FLAME data shows that [the] FlowTriever is an important new treatment option that offers a dramatic improvement in survival.”