麻豆传媒

CHICAGO -- The days of experimentation are far from over for transcatheter aortic valve replacement (TAVR), with efforts underway to bring pacemaker needs and paravalvular leaks down and improve durability -- the latter being especially important for younger patients.

Investigators offered up the latest in design and program updates for several TAVR devices, some more well-known than others, here at the Transcatheter Valve Therapy meeting organized by the Cardiovascular Research Foundation.

CoreValve/Evolut from Medtronic

Medtronic looks to add to its CoreValve line of self-expanding transcatheter heart valves, which already includes the current Evolut R and Evolut PRO devices associated with good hemodynamic performance and non-inferiority to surgery among low-risk patients.

For the next generation of Evolut valves, a major new design goal is a delivery profile as low as 12 F, according to Jeffrey Popma, MD, of Beth Israel Deaconess Medical Center in Boston. Other goals include a decrease in paravalvular leaks (keeping mild leaks under 10%), a reduction in conduction disturbances, better coronary access, symmetric deployment, and complete retrievability and repositionability.

The Evolut PRO came to be after designers added an outer porcine pericardial wrap to the Evolut R.

Sapien from Edwards Lifesciences

The latest addition to the balloon-expandable Sapien line is the Sapien 3 Ultra, which has the same frame and leaflet design as the Sapien 3, said John Webb, MD, of St. Paul's Hospital and Vancouver General Hospital in British Columbia.

Redesigned features include a 40% taller outer skirt and a valve that is crimped directly on the balloon. The device comes in four sizes (20-29 mm) and is compatible with 14-F sheaths.

The Ultra got Europe's CE Mark last fall and continues to be investigated in the ongoing in 100 intermediate-risk patients.

Lotus from Boston Scientific

The repositionable Lotus Edge builds on several features that were added to fix the first-generation Lotus valve's 26% pacemaker rate.

That rate is now down to 12% with the addition of Depth Guard (which limits the depth of implant), radio-opaque markers (which eliminate the need for multiple views during locking), and a flexible, curved delivery system, according to Didier Tchétché, MD, of Clinique Pasteur in Toulouse, France.

Design goals for the next-generation Lotus Mantra include reduced valve height, a lower delivery profile, and elimination of the need for locking assessment.

Other Hopefuls

Centera is Edwards Lifesciences' other TAVR product and features the same bovine pericardial tissue as the Sapien family on a . It is designed for single-operator use thanks to a motorized handle and uses dry leaflet tissue processing for easy storage and preparation.

Documented pacemaker rates are 6.0% at 1 year and 8.3% at 2 years with the Centera. Implanted patients also show no more than mild aortic regurgitation at 1 and 2 years. The U.S. pivotal clinical trial ExCEED is still in enrollment.

Another valve from Boston Scientific, the Acurate neo, has been associated with a 9.9% pacemaker implantation rate and 3.4% moderate paravalvular leaks at 12 months in a post-market registry. The newer Acurate neo2 will keep the device's self-expanding nitinol frame and supra-annular positioning while adding better sealing features in the form of inner and outer pericardial skirts.

Abbott's Portico was found to have a 19.5% pacemaker rate and 2.6% moderate paravalvular leakage in 1-year data from the PORTICO I study. The next iteration of this device is to have an active sealing cuff, increased radial force, a better seal zone, and fit an annulus range of 19-30 mm.

Chinese company Venus MedTech is working on the Venibri, a retrievable version of the self-expanding Venus A valve featuring high radial force and integrated cerebral protection. The device also comes with pre-crimped, dry tissue. In an initial 17-patient trial, two patients developed moderate leakage at 1 year and two patients needed a new permanent pacemaker.

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