The company’s cerebral protection system has been studied during TAVR as part of post-market evaluation of embolic debris captured in its dual-filter system.
Recent studies have raised concerns about adverse cerebrovascular events during the TAVR procedure and shortly thereafter. The incidence of early, acute cardiovascular events ranges from 2-6% in different studies. Early cardiovascular events have been associated with embolic debris released during the procedure; however, the etiopathology of the embolized material was uncharacterized.
Claret Medical sponsored a study of 40 patients undergoing TAVR with the use of the company’s dual filter–based embolic protection device in order to determine the composition of embolic material released during TAVR.
Macroscopic material liberated during the TAVR procedure was captured in the device filter baskets in 75% of cases. The debris was histopathologically analyzed by an independent core lab (CVPath Institute, Gaithersburg, Maryland). The captured material varied in size from 0.15 to 4.0 mm. Overall, thrombotic material was found in 52% of patients, and tissue fragments compatible with aortic valve leaflet or aortic wall origin were found in 52% of patients.
After receiving CE Mark approval in 2014, Claret Medical initiated the SENTINEL-H post-market observational study to assess real-world performance of the Sentinel cerebral protection system (CPS). With Professor C. Naber from Essen, Germany as the Principal Investigator, SENTINEL-H was a prospective, all-comer study that enrolled 217 patients across six centers in Europe. Results of the study were presented in May 2016 at the EuroPCR scientific symposium in Paris, France.
The study was designed to evaluate the effectiveness of the Sentinel CPS in capturing debris during TAVR procedures that utilized a variety of TAVR valves in a real-world clinical setting. The primary endpoint of the study was the rate of capture and the histopathologic analysis of the embolic debris, including total and per-filter embolic debris dimensions, area and debris type characterization; this work was completed and reported by an independent core-lab (CVPath Gaithersburg, USA)
The results showed that the Sentinel CPS system can be successfully deployed in patients undergoing TAVR in a real-life clinical environment.
Cerebral debris was captured in 99% of the patients (Fig 1). The types of debris captured in the filters included arterial wall, valve tissue, calcification, foreign material and organizing thrombus. Acute thrombus was almost always found in association with other tissue and/or other embolized material, showing that thrombus is not created by the filters. This is debris that would have otherwise entered the cerebral circulation.
There were a mix of older and new generation TAVR valves implanted in this study, described as: self-expandable (SE), balloon-expandable (BE) and mechanically-expandable (ME). (Fig 2) While debris was captured with all valve types, self-expanding valves appear to result in higher rates of embolized valve tissue than balloon-expandable valves (71% vs 43%). Self-expanding TAVR valves may also result in higher rates of arterial wall and calcification debris versus balloon-expandable valves.
Regardless of the TAVR valve type that is implanted, debris was captured and retrieved in virtually every case suggesting that cerebral protection has clinical value even with new generation TAVR valves.
The Sentinel CPS has received the CE Mark and is commercially available in Europe. It is limited to investigational use in the United States.