Six-month results from the FlowTriever All-Comer Patient Safety and Hemodynamics Register (flash) Register Today it was presented as the latest clinical paper at the Scientific Society for Cardiovascular Imaging and Interventions (SCAI) 2023 Sessions. The multicenter prospective study found that patients with pulmonary embolism (PE) treated with mechanical thrombectomy showed significant improvement in symptoms, quality of life, and heart function.
Pulmonary embolism, a blood clot that begins in a blood vessel in the body and travels to the lung, is the third leading cause of death from cardiovascular disease after heart disease and stroke. PE survivors often experience decreased quality of life after treatment including persistent shortness of breath and decreased ability to exercise. Preliminary data show the safety and efficacy of long-lumen thrombectomy, the removal of blood clots using a mechanical catheter, for the treatment of PE rather than current standards of care, and anticoagulants combined with the use of catheter-based interventions, but limited data exist on long-term outcomes.
FLASH is a prospective, single-arm, multicenter registry for acute PE patients treated with the FlowTriever System (Inari Medical). Six-month clinical outcomes were evaluated, including the Medical Research Council (Mmrc) dyspnea score, right ventricular (RV) function, 6-minute walk test (6MWT), and PEmb quality of life (QoL) scores. The trial included 800 patients at 50 US sites, 54.1% of whom were male and the mean age was 61.2 years. Anticoagulants were reported in 32.1% of patients, 77.1% were classified as moderate-high risk and 8% as high-risk. Most patients (74.8%) completed all study visits with a six-month follow-up.
In the 599 patients who completed a six-month follow-up, multiple statistically significant functional and clinical improvements were reported over the study period.
- The proportion of patients with normal RV function on echocardiography increased from 15.1% before thrombectomy to 95.1% and 94% had normal pulmonary artery pressure.
- All-cause mortality was 0.3% at the 48-hour visit, 0.8% at the 30-day visit, and 4.6% at study exit (median=199 days post-treatment).
- The patient’s tolerance and symptoms also improved significantly after treatment. The distance the patient could walk in six minutes increased from 180 meters after 48 hours of treatment to 398 metres.
- The mean mMRC dyspnea score improved from 3.0 at baseline to 0.0 (P < 0.0001)
- The percentage of patients with normal RV function on echocardiography increased from 15.1% at baseline to 95.1% (P < 0.0001), and RV systolic pressure ≤40mm Hg improved from 28.4% at baseline to 93.9%.
- The prevalence of chronic thromboembolic pulmonary hypertension over six months was 1.0% and chronic thromboembolic disease 1.9%.
It is encouraging to see the dramatic and rapid improvement in both the clinical outcomes and the daily activities of our patients, such as walking without running out of breath. We hope that these FLASH data will be the next step in understanding the importance of thrombectomy as a treatment option for patients that is seen in their recovery and improved quality of daily life. “
Sameer Khandhar, MD, assistant professor of clinical medicine at the Perelman College of Medicine at the University of Pennsylvania Penn-Presbyterian Medical Center in Philadelphia, Pennsylvania. And participated in the study
In addition to the significant improvement in patient symptoms, heart function, and quality of life, a decrease in long-term mortality has also been reported after treatment with the FlowTriever System. These data suggest that rapid thrombus extraction may prevent long-term effect in PE patients, although comparative data regarding conservative management are needed.