She said this year’s TVT was exciting as it was the first in-person meeting since 2019, and many new technologies were discussed during the sessions. This included the first reports of the clinical use of new technologies for the mitral valve and the tricuspid valve.
“The question is which ones will be discontinued and which of these technologies will become the most successful,” Asgar said. “We also need to find the rhythm of these technologies. When are we going to use transcatheter edge-to-edge (TEER) repair versus who is going to need replacement.”
There were high hopes that other transcatheter valve technologies would see a similar path taken by transcatheter aortic valve replacement (TAVR), moving from the bench to clinical practice in a relatively short time with excellent results. However, several TVT experts have described the aortic valve as the low hanging fruit, and there are issues that need to be addressed for other valve positions.
The mitral valve is more “D” shaped, has a very small landing area to place a valve, has tie cords attached to the leaflets and any device placed there should have a small profile to avoid hanging down in the left ventricular outflow tract (LVOT) to prevent blood flow obstruction. Anchoring a valve in this dynamic high-pressure environment may require different strategies beyond simply expanding the valve body outward. This led to the development of ways to clip the edges of the valve to the annular space or to sandwich the native valve between two sections of a transcatheter valve.
“One of the things we’ve learned is that the mitral anatomy is much more complex than the aorta, so there have been many different strategies and technologies developed to implant a mitral valve,” Asgar explained.
These include anchoring the device to native leaflets or radial force on the valve annulus. The latest approach was showcased by startup supplier Innovalve at TVT 2022. Asgar said it uses a set of star-shaped arms to twirl and wrap the taut strings and valve leaflets and the valve is deployed on the wrapped components of the valve to anchor it better and possibly remove the LVOT issues of the native flyers.
This complexity also varies from. Patient-to-patient, requiring intense pre-procedural screening to plan implants and decide if a patient’s anatomy is suitable for a transcatheter valve implant.
“Depending on the device, you can have scouting failure rates between 20% and 65%, depending on the size of the valve, how it anchors, and the impact on the LVOT” , explained Asgar. “Some of these devices are better suited for calcium, although the majority of devices are targeted for mitral regurgitation.”
Computed tomography (CT) is used to prescreen patients and images are used to model the valve in a simulated environment to verify LVOT sizing and obstruction.
“Sometimes modeling with CT doesn’t reflect what’s going on in real life,” she said. “So the big challenge is really the obstruction of the LVOT, the movement of the anterior leaflets in the LVOT, which can make it worse, and how we can mitigate that.”
She said there are techniques to overcome LVOT obstruction such as LAMPOON and SESAME to use transcatheter cutting wire to cut native valve leaflets or perform myectomy to ensure unobstructed LVOT. However, Asgar said it’s best to avoid LVOT issues that require a separate procedure.
The first transcatheter mitral valves have gone through clinical trials. Asgar said there is a lot of interest in the ongoing SUMMIT clinical trial of the Tendyne device against TEER. She said another big trial is APOLLO, Medtronic’s Intrepid Valve clinical trial.
Tricuspid transcatheter devices likely to win FDA before new mitral valve technology
Despite the great interest in mitral devices, Asgar and other TVT experts said tricuspid valve devices are likely to gain a head start. Mitral technologies and get FDA clearance faster.
“In the tricuspid, we don’t have this problem of LVOT obstruction,” Asgar explained. “We may have size issues and AV block issues that require pacemakers, but we realized there are a lot of these patients out there. mitral valve, so it’s really a population that has an unmet need. The surgical data on iOS valve replacement isn’t great, but what we’re seeing with transcatheter valve placement is very encouraging.”
Due to surgical results, the tricuspid valve has been overlooked until recently, as transcatheter valves offer a new, much less invasive approach.
She said there is excellent data from the Edwards Lifesciences Evoque tricuspid valve and the tricuspid TEER. She said the TRILUMINATE trial will soon end its enrollment and provide the first data on TEER versus medical therapy.
There have been concerns about treating patients with pacemaker or ICD leads that cross the tricuspid valve into the heart, but Asgar said there is preliminary data showing that TEER can still be performed and that a reasonable result can be obtained.
TMVR, TTMV and related TAVR content:
VIDEO: Transcatheter tricuspid devices likely to gain FDA clearance ahead of new mitral advancements – Azeem Latib, MD
VIDEO: The State of TAVR in 2022 — Interview with Michael Mack, MD
VIDEO: MitraClip vs Surgical Mitral Valve Replacement – Interview with Joanna Chikwe, MD
VIDEO: Transcatheter Myectomy to Prevent LVOT Obstruction During Mitral Valve Replacement – Interview with Adam Greenbaum, MD
Links to all last minute structural heart studies at TVT 2022
VIDEO: How to Build a Structural Cardiac Program — Interview with Charles Davidson, MD
Find more structural core content and video