The HighLife transseptal mitral valve replacement (TSMVR) device may be suitable for use in patients who have mitral regurgitation (MR) and no alternative therapy to cardiac surgery or other transcatheter treatment and are not responding to guideline-directed medical therapy (GDMT), a new study shows.

Stephen Worthley, MBBS, PhD, of the Macquarie University Hospital, Sydney, presented these results during a late-breaking trial session Wednesday at EuroPCR 2023 in Paris.

Patients with grade 3 or greater MR and high surgical risk have few alternative therapies to surgical interventions or catheterization. This study evaluated the feasibility, safety and performance of the HighLife TSMVR system in this patient group at 30 days. Follow-up through 5 years is planned.

The study was sponsored by the device manufacturer, HighLife SAS.

In transcatheter aortic valve replacement, the transcatheter heart valve (THV) is placed in a fibrous, inflexible annulus, but the mitral valve annulus is not as stable an environment for implanting a THV, Worthley explained during a press conference at EuroPCR.

To overcome this issue, HighLife device has a unique valve-in-ring concept in which a subannular implant is placed underneath the mitral valve to capture all of the chords, acting like a pseudo-annulus to accept antegrade delivery of the hourglass stent frame across the mitral valve through transseptal access, he said.

“That’s a new technique, basically, in interventional cardiology to cross the aortic valve retrogradely, then try to capture all of the chords and deliver the subannular implant,” Worthley said.

This single-arm, prospective, multicenter, non-randomized, open-label study enrolled 52 consecutive patients (mean age=75.2 years, 38.5% female, 87% with secondary MR).

All patients left the catheterization laboratory alive.

The device was successfully delivered and retrieved in 94% of patients (49 of 52). In two patients, guidewire looping could not be completed because of the patient’s anatomy or condition, which prevented implantation of the mitral ring and valve. One other patient’s valve was delivered low and led to emergency cardiac surgery.

Emergent surgery or reintervention was not needed in 92% of patients (48 of 52). Besides the patient with low valve delivery, two other patients did have the valve properly implanted but, because of their anatomy, the device moved immediately into the left ventricle, which required both patients to undergo surgery. Another of these patients was treated with balloon inflation because of a perceived high gradient.

The technical success rate was 88%.

At 30-day follow-up, seven patients had died (13.5%). Fifteen patients (28.8%) experienced a major safety event, with all-cause mortality being the most common (seven patients).

Worthley emphasized that this was “a very sick patient population.” He added that operators learned how to better implant the device with experience.

None or trace or MR was observed in just over 90% of the 40 patients available at 30-day follow-up.

“Most of the implanting physicians had no prior experience with this technology of the ‘valve in ring’ concept,” Worthley said. “The outcomes show very acceptable clinical and excellent echocardiographic outcomes.”