Assessment of the Safety and Effectiveness of the FLOWer Antiembolic Filter Supporting Transcatheter Aortic Valve Implantation

Background: Embolic events are life-threatening complications of transcatheter aortic valve implantation (TAVI) with clinically relevant stroke rates of 2%-4%. Aims: This study aims to evaluate the safety and effectiveness of FLOWer, a novel embolic protection device (EPD) used in TAVI procedures. Methods: Data on the FLOWer device were obtained from its CE-mark clinical trial (the NAUTILUS study, NCT04704258). Safety outcomes were the 30-day rate of major adverse events (MAEs, including all deaths, ischemic strokes, and acute kidney injury), while effectiveness data consisted of the number of particles captured by the filter during the procedure. These data were compared with benchmark values from the EPD literature. In addition, the total number (TNL) and volume (TVL) of new brain lesions were evaluated. Results: A total of 52 intention-to-treat (ITT) patients were considered, 45 of whom were per protocol (PP) patients. The rate of 30-day MAEs for the PP population was 2.2% (1/45% vs. 14.3%, p = 0.0082); no strokes were observed. The median number of captured debris larger than 60 μm was 213 (IQR: 128-315 vs. 46.1, p < 0.0001), and larger than 150 μm, 105 (IQR: 60-190 vs. 41.6, p < 0.0001). The median TVL and TNL per patient were 291.7 mm3 (IQR: 98.5-630.7 mm3) and 4.5 mm3 (IQR: 2.0-8.3 mm3), respectively. Conclusions: The use of FLOWer during TAVI was found to be feasible and safe, with a low incidence of MAEs and a reduced number and volume of new brain lesions. The significant amount of debris captured compared to similar devices demonstrates effective device performance.