Why is this study important? 

Despite the increasing frequency of the use of large-bore mechanical thrombectomy for patients with pulmonary embolism using the Inari FlowTriever system, the long-term effects of this therapy on right ventricular function and patient quality of life has remained unknown.

What question was this study supposed to answer? 

FLASH (FlowTriever All-Comer Registry for Patient Safety and Hemodyamics) is a prospective, single-arm study evaluating right ventricular function and quality of life outcomes in intermediate or high risk pulmonary embolism patients treated with FlowTriever large-bore mechanical thrombectomy. 6 month data is reported in this publication including the 75% (599) of patients who completed 6 month follow up.

What did the study show? 

All –cause mortality was 0.3% at 48 hours post-thrombectomy, 0.8% at 30 days and 3.6% at 6 months. There were no deaths, pulmonary injuries or cardiac injuries attributable to the FlowTriever system. A significant decrease in echocardiographic parameters of right ventricular strain (RV/LV ratio) and significant improvement in right ventricular function following thrombectomy were demonstrated. These improvements were most notable at 30 days and sustained through 6 months.

Importantly, functional status (dyspnea), quality of life scores, and exercise capacity (walking distance) showed significant improvement at 48 hours and patients continued to improve over the 6 month follow-up period. 90.1% of patients reported “no or mild dyspnea” at 6 months post-procedure.

Randomized controlled trials will be important to further investigate the long-term benefits of FlowTriever mechanical thrombectomy in patients with pulmonary embolism and to determine which patients benefit the most from the procedure. However, this study does provide some evidence that the procedure may have short and long-term benefits and corroborates the safety of the procedure, which has been demonstrated in other trials.