Emerging data supports transcatheter techniques to treat primary mitral regurgitation, according to KK Yeo (National Heart Center, Singapore) who presented at PCR Valves 2020 (22–24 November, virtual) discussing the latest developments in edge-to-edge repair for primary mitral regurgitation.
Yeo discussed data from the EXPAND Registry, documenting real-world outcomes from the third generation MitraClip (Abbott) NTR and XTR systems, as well as looking ahead to further studies and technological developments in the field.
“What is important and impressive is that procedure time had improved from 135 minutes to 82 minutes in the EXPAND registry, and the length of stay has improved from three days to one day in terms of the median duration,” said Yeo, commenting on data initially presented at the American College of Cardiology/World Congress of Cardiology’s virtual scientific sessions (ACC.20/WCC Virtual) in March, with further data also presented during a late-breaking session at PCR Valves.
Further evidence on the efficacy of the device are expected to be gathered through the REPAIR MR trial, Yeo commented, which will compare the clinical outcomes of the Mitraclip to surgical repair in patients with severe primary MR who are at moderate surgical risk.
Additionally, Yeo highlighted data from the CLASP trial, evaluating the safety and performance of the Pascal system (Edwards Lifesciences), which was presented in the summer, and found that the device was associated with a low complication rate and high survival rate in the treatment of mitral regurgitation.
These developments lead Yeo to conclude that new generation devices “offer more treatment options” and added that through the emergence of the Pascal device, competition has arrived in the mitral device market—representing a positive outlook for transcatheter treatment options.
Following Yeo, Stephan Baldus (University Heart Center Cologne, Cologne, Germany) appraised the evidence for edge-to-edge repair in secondary mitral regurgitation patients. “Within the last couple of years, we have witnessed a sound body of evidence showing that secondary mitral regurgitation is not only a bystander, but it’s a driver of disease in patients with systolic heart failure,” he said, in the opening slide of his presentation.
Baldus commented on the rapid adoption of transcatheter mitral techniques in functional mitral regurgitation patients, commenting that the edge-to-edge repair is the “driving procedure for these patients in functional mitral regurgitation”. He commented that in terms of safety, the procedure has been shown to be safe out to five years, “If we combine all of this we can bascially say that mortality throughout these registries is below 4% nowadays, the stroke rate is exceptionally, below 1% and single leaflet detachment is below 2%, so it is a really safe procedure for secondary mitral regurgitation.
With respect to efficacy edge-to-edge repair is non-inferior to mitral valve surgery in patients with functional mitral regurgitation, Baldus commented. “The TVT Registry, the EXPAND Registry, as well as randomised trials in these patients, show that procedural success has increased to over 90% with 75% or more indicative of a mitral regurgitation grade below 1 or 90% of these patients showing an MR grade of below 2 in functional regurgitation.
“We have to be good at reducing mitral regurgitation because we know that the grade of residual MR determines the fate of the patient. Patients who are leaving the hospital with an MR grade of 1 or below actually have the best prognosis. It is interesting to see that we need to be sure that this is sustained over the next 12 months.”
In a later session, looking at innovations in surgical and transcatheter mitral valve intervention, Paul Sorajja (Minneapolis Heart Institute, Minneapolis, USA) discussed the latest developments in transcatheter mitral valve technology.
“While we all know that transcatheter mitral valve replacement was pioneered with transapical devices, many new technologies have been moving towards the transseptal approach,” Sorajja commented. He noted that Sapien M3 (Edwards Lifesciences), Evoque (Edwards Lifesciences), Alta (4C Medical) are among the devices to have been implanted using this approach to date.
“One of the newest entrants is the Medtronic Intrepid system,” he said. “This is the same valve that was used in a transapical approach as part of the feasibility study and this is now a transseptal system that is 35 French, and the first patient was treated in February. There are plans for an early feasibility study at 15 patients among those who are not eligible for surgery.”
Sorajja also mentioned the HighLife Valve (HighLife Medical)—describing this as a hybrid approach of a transvenous and a transarterial system in which a ring is used to manage the mitral leaflets and also anchor the device. “This approach helps to minimise device profile and potentially enables patients who were previously excluded due to potential LVT obstruction,” he said
For repair technologies, he highlighted the Millipede system by Boston Scientific which he said is shortly to begin an early feasibility study. ”This highlights a strong desire for a toolkit approach for catheter interventions akin to open surgery,” he commented, adding that “percutaneous angioplasty could be an adjunct as it is permissive technology or be a standalone therapy”.
Finally he added that the ability to perform transcatheter repair as well as replacement in the same patient is also emerging. He detailed a first-in-human example of a patient who had initially had successful MitraClip implantation, but recurrent MR. His team performed percutaneous laceration of the tissue bridge followed by placement of the Tendyne (Abbott) TMVR device.
“It is an example of a change in the field where we may not have to exactly choose between transcatheter repair and replacement in a given patient, and that one may simply be able to follow the other if an initial repair fails.”