Embolic Protection Devices for TAVR Show Promise
SAN FRANCISCO, CALIF.—While studies have shown a substantial stroke risk with TAVR procedures, a number of new devices may help protect against this risk, and early clinical experience has been promising.
“The general consensus is that in about two-thirds of patients you have some emboli that are happening in the brain,” said Samir Kapadia, MD, a professor of medicine at the Cleveland Clinic in Ohio, during a scientific session yesterday. In various studies, the risk of stroke has ranged from 1% to 7%.
Early results with two deflection devices deployed in the aortic arch were presented during the session. First, Pieter R. Stella, MD, PhD, of the University Medical Centre Utrecht in the Netherlands, noted that the SMT Embolic Protection Device is easy to use and covers all cerebral branches from the aortic arch.
“Not all patients are alike, there are a lot of different anatomies, and a lot of different perfusion pathways to the brain, and maybe one device is not suitable for all anatomies,” Stella said.
In a small feasibility study, 15 patients received the SMT device during a TAVR procedure. One patient suffered a transient ischemic attack (TIA) at 4 days following the procedure, and one suffered a stroke after 5 days. MRI showed a 50% reduction in new cerebral lesions compared to 25% in control patients. Based on this early work, a larger study is planned, which Stella said will begin in December or early January.
Another device, the Embrella Deflector (Edwards Lifesciences), is also designed to cover the cranial branches during TAVR. In a study with the device used in 20 patients—with 18 available for final analysis—100% achieved coverage of the brachiocephalic artery and the left common carotid artery. According to Ulrich Gerckens, MD, of St. Petrus Hospital in Bonn, Germany, 60% of the patients also received additional coverage of the left subclavian artery.
Post-procedure MRI in 15 of the patients found new cerebral lesions in 11 subjects, with an average of 4.36 lesions per patient, and 3.2 lesions per patient when subjects without any lesions were included. Gerckens said this compared favorably with studies of patients undergoing TAVR without embolic protection.
“It is proven that [the device] can reduce hits identified by MRI, but the clinical relevance of these data are still unknown,” Gerckens said. “Further studies are needed to prove this concept, but the initial clinical experience is that it is easy to handle the device.”
Another device uses a different approach to embolic protection, with dual filters placed in the two carotid arteries. Unlike the deflection devices, the Claret CE Pro System (Claret Medical) (see Figure) actually captures any debris that moves into the arteries.
In a study involving 40 TAVR patients, there were no procedural TIAs or minor or major strokes. One patient suffered a minor stroke within 30 days of the procedure, two suffered major strokes, and six patients died, though none of these were related to the device. Christoph K. Naber, MD, PhD, of the Contilia Heart and Vascular Center at Elisabeth Krankenhaus Essen in Germany, said that the first seven patients received a first-generation device, and it was deployed successfully in five patients. A newer version of the device was subsequently deployed successfully in 30 out of 33 study patients. The average delivery time also dropped significantly from the first group to the second, from over 11 minutes to over 5 minutes (P<.05).
“The use of the Claret CE Pro system to protect the brain from embolic debris during [TAVR] is feasible and safe, and I have to say it is astonishingly easy,” Naber said
- Drs. Gerckens and Kapadia report no relevant conflicts of interest.
- Dr. Naber reports receiving grant/research support or consulting fees/honoraria from Biosensors, Biotronik, EuroCor, Medtronic, Mitralign, Sadra Medical and Stentys.
- Dr. Stella reports serving on the scientific advisory board for SMT Medical.