What’s The Future For Treating Mitral Valve Disease: Repair, Replace, or Combination Approaches?

CHICAGO, IL—In a TVT 2019 session devoted largely to crystal balls and speculation, interventional cardiologists and surgeons discussed what comes next for therapies aimed at treating mitral regurgitation (MR) after the successful COAPT trial, with some experts arguing that the future belongs to transcatheter mitral valve replacement (TMVR) therapy and others envisioning greater use of transcatheter mitral repair devices, used either alone or in combination.   

And while the session hinged on determining which treatment approach would “win” in the next 5 to 10 years, several physicians said the question is largely irrelevant.

“To believe that we’re going to have one winner in the mitral space, and to believe that we’re going to have a one-shot-deal therapy, is delusional,” Philippe Généreux, MD (Gagnon Cardiovascular Institute, Morristown Medical Center, NJ), told TCTMD. “The mitral valve is complex and we’re going to need different tools to address all the different pathologies, the different mechanisms, and the different patients we see.”

Francesco Maisano, MD (University Hospital Zürich, Switzerland), made a similar argument, noting that just as surgeons deploy a combination of repair and replacement strategies based on anatomy and the mechanisms of MR, so too will interventional cardiologists. “You can’t treat every patient with one device, this is very simple,” said Maisano. “In surgery, combining multiple maneuvers is standard because it optimizes early results and provides longer durability.”

In surgery, for example, annuloplasty has been routinely added to the Alfieri stitch, the surgical edge-to-edge mitral valve repair (that the MitraClip mimics), said Maisano. Whether combined transcatheter edge-to-edge repair with MitraClip and an annuloplasty ring will improve clinical outcomes as it does for surgical patients remains to be seen. At present, annular remodeling and leaflet repair is feasible and effective in selected patients, and this may be done in a staged procedure to assess MR before leaving the catheterization laboratory. For patient-centered care going forward, said Maisano, a “complete mitral toolbox” will be critical.

Imagine Mitral Valve Repair in 5 to 10 Years

During the TVT session, moderator Howard Herrmann, MD (Penn Medicine, Philadelphia, PA), played devil’s advocate and asked cardiovascular surgeon David Adams, MD (Icahn School of Medicine at Mount Sinai, New York, NY), whether transcatheter repair and replace strategies were set to eliminate surgery for the treatment of MR. Adams replied that for heart failure patients with a limited a life expectancy the future belongs to transcatheter-based technology.

“I’m not sure which one is going to win,” said Adams. Although he was impressed with several of the presentations, he said if he had to had to “put his quarter” on one approach it would be TMVR. “As long as it fits, that’s definitive therapy for a patient with limited life expectancy,” he said. “Remember, even in the COAPT study with MitraClip, mortality is excessive. It’s a high-mortality disease so it’s really about quality of life and the reduction in MR.”

During the session, Paul Sorajja, MD (Minneapolis Heart Institute Foundation, Minneapolis), spoke in favor of TMVR, predicting that once the technology is refined, it will become the preferred treatment for patients with severe MR. To make his case, Sorajja highlighted data from 2,952 patients treated with MitraClip included in the STS/ACC TVT Registry showing that patients left with grade 0/1 MR had better 12-month survival than did patients with grade 3/4 MR after the procedure.

“A MitraClip failure portends a very poor prognosis,” said Sorajja, “but even when you look at grade 2 versus grade 1 MR, there is also a signal of worse mortality with residual moderate MR.” While there are limitations to registry data, the study should be a reminder to physicians that, in an ideal world, no patient would be left with moderate after a MitraClip. He added that the learning curve to achieve excellent outcomes with MitraClip—that being better MR reduction without an increased risk in complications—is steeper, with considerable experience needed to achieve surgery-like results.

Referring to their experience with the Tendyne (Abbott) TMVR technology, Sorajja reported data showing that 98.9% of the first 100 patients treated had no MR upon discharge and 98.4% had no MR at 12 months. “And this can be achieved with an excellent safety profile,” said Sorajja. The procedure is more complex with the transapical approach, and patients spend more time in the hospital and intensive care unit than those treated with MitraClip, but procedure times aren’t that much longer, he said.

Brian Whisenant, MD (Intermountain Heart Institute, Salt Lake City, UT), on the other hand, said he believes transcatheter mitral annuloplasty will replace leaflet technologies in the future and highlighted several transcatheter mitral valve annuloplasty devices, including Cardioband (Edwards Lifesciences), Carillon (Cardiac Dimensions), and Millipede Iris (Boston Scientific), as well as the AccuCinch ventricular repair system (Ancora Heart). In addition to presenting data from their early experiences with Cardioband, he reported 2-year data from the Cardioband CE Mark study showing that 96% of patients treated with the device had “sustained and significant MR reduction.” This translated into improvements in NYHA class, Minnesota Living with Heart Failure Questionnaire scores, and the 6-minute walk test.

“I’m a huge fan of MitraClip and edge-to-edge repair,” said Whisenant. “Nonetheless, I recognize the limitations of residual recurrent MR, mitral stenosis, and the prevention of future options, such as transcatheter valve replacement.” In a recent head-to-head comparison of Cardioband versus MitraClip presented at EuroPCR 2019, there were greater improvements in NYHA class and mean pressure gradients with Cardioband, as well as a lower risk of mortality and rehospitalization, he said.

Whisenant also noted that additional mitral valve repair systems are being tested in early clinical trials, or have received CE Mark approval in Europe, including the Pascal (Edwards Lifesciences) leaflet capture transcatheter valve repair system, the NeoChord (NeoChord Inc) minimally invasive prolapse repair technology, and the Harpoon (Edwards Lifesciences) repair system for beating-heart chordal implantation.

Multiple Winners

With the possible introduction of different technologies in the next few years, Généreux said there is a need for “multiple winners” to accommodate all the different mitral valve pathologies, but added that he believes edge-to-edge repair with MitraClip will endure. But while MitraClip is a mature technology that has proved itself in the COAPT trial, “there are a lot of patients that aren’t eligible for edge-to-edge repair and we’re going to need to move to other therapies,” said Généreux.  

Regarding combined procedures, use of the MitraClip as a first option would allow physicians leeway to deploy these other therapies, he said.

“Maybe during a case you see you have an increased gradient, or its not suitable any more, or you can’t deploy the clip,” said Généreux. “Then you have to move to another strategy, maybe annuloplasty or TMVR. Right now we don’t have all these devices commercially available so we’re only speculating that it’s appropriate to start with MitraClip, but I do believe that in the future we’ll be able to start with a therapy that is best for the patient and to evolve as the therapy fails.”

Herrmann pointed out that a future that involves multiple fronts to treat MR is still many years away, and that the COAPT results were “pretty amazing” in functional MR without an annular reduction strategy. As such, why would physicians need to consider annuloplasty?

Maisano agreed, noting that after COAPT, “everything else looks bad.” Annuloplasty is more complicated and takes more time, he said, but he urged physicians to remember that annuloplasty is associated with lower mean pressure gradients and it leaves the door open for future procedures. Nonetheless, based on existing data, as well as the large experience with MitraClip, future therapies have a high hurdle to clear, said Maisano.