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Mitral Valve Repair Devices Go Head-to-Head, and the Top Spot Belongs to…

BOSTON — The Pascal device for edge-to-edge mitral valve repair was as safe and effective as the MitraClip device, the pivotal CLASP IID trial showed.

In a pre-specified interim analysis of the first 180 patients enrolled, Pascal was non-inferior for the primary effectiveness endpoint of proportion of patients with mitral regurgitation no worse than 2+ at 6 months (96.5% vs 96.8%), with a one -sided 95% lower confidence bound of -6.2% that fell well within the prespecified margin of -18%.

The composite major adverse event (MAE) rate at 30 days was likewise similar between groups at 3.4% versus 4.8%, reported D. Scott Lim, MD, of the University of Virginia Health System in Charlottesville, at the Transcatheter Cardiovascular Therapeutics (TCT) meeting hosted by the Cardiovascular Research Foundation. The findings were simultaneously published in JACC: Cardiovascular Interventions.

Again, the lower bound for the 95% confidence interval of 5.1% fell well within the generous 15% non-inferiority margin in the findings (set based on the EVEREST II trial) for that composite of cardiovascular mortality, stroke, myocardial infarction, new need for renal replacement therapy, severe bleeding and urgent mitral valve reintervention, whether percutaneous or surgical.

“The Pascal system is a beneficial therapy for significant symptomatic degenerative MR, expanding transcatheter treatment options for prohibitive surgical risk patients,” Lim stated.

The trial formed the basis for FDA approval of the Pascal Precision system for the treatment of patients with degenerative mitral regurgitation (DMR), which manufacturer Edwards Lifesciences announced Thursday.

While results on the full cohort are expected out in the first quarter of 2023, perhaps at the American College of Cardiology meeting, all will be enrolled in the TVT registry for 5 years of follow-up.

“I’m quite impressed by the durability of the results at 6 months looking at MR,” said session moderator Jane A. Leopold, MD, of Brigham and Women’s Hospital in Boston, noting that MitraClip results have shown some deterioration in durability over time .

Lim responded by noting the relatively short follow-up in the trial and lack of statistical power for change in MR over time. But “the whole field of transcatheter repair is moving forward. These results are getting better and better, such that they now are essentially like the results of a very good surgeon. Clearly we have to see this in the longer term,” he added.

However, Anita W. Asgar, MD, of the Montreal Heart Institute, cautioned that about comparing devices based on fairly small numbers.

Who Gets What

“The highlight of this in my mind is that we are coming to a moment in which we have options,” said TCT press conference panelist Federico M. Asch, MD, of MedStar Health in Washington. “There are going to be patients that may be better candidates for one or the other. I don’t think we will have that answer right now.”

While “very comforting” in terms of transcatheter edge-to-edge repair safety and effectiveness overall with both options, “for individual operators it will come down to cost, it will come down to ease of use, and operator preference of one device over the other,” argued session panelist Bernard Prendergast, MD, of St. Thomas’ Hospital and Cleveland Clinic London.

Subgroup analyzes turned up no differentiating factors for greater benefit of one device over the other, Lim noted. However, I suggested that design features of the two platforms might lend themselves to different anatomies, for example the smaller size of Pascal could prove helpful for smaller annuli whereas the stronger mechanical closure of MitraClip could benefit cases with thick or calcified leaflets.

The trial aims to enroll a total of up to 300 adults with symptomatic, grade 3+ or 4+ degenerative MR by transthoracic echocardiography or echocardiography on core lab assessment who are at prohibitive surgical risk, and are candidates for either edge-to-edge mitral valve repair device, as determined by the local heart team. Participants are randomized 2:1 to Pascal or MitraClip.

Patients suitable for treatment with Pascal, but not for the MitraClip system, based on anatomical characteristics were considered for enrollment in the PASCAL IID registry.

Extended Criteria

That registry showed “acceptable” adjudicated MAE rates of 11.2% at 30 days, reported Jörg Hausleiter, MD, of Klinikum der Universität München in Germany, at the same TCT session.

And treatment with Pascal reduced MR to grade 2+ or less in 92.4% of the 98 patients enrolled in the registry due to more complex anatomy that ruled out MitraClip use when they already weren’t candidates for surgery. New York Heart Association class improved significantly as well.

Hausleiter noted that these patients had not just more complex anatomy but also clinical risk features that suggested a more medically fragile population than in the main trial, including some 70% with atrial fibrillation.

“The Pascal system is beneficial for prohibitive risk DMR patients with complex mitral valve anatomy historically considered less suitable for [mitral transcatheter edge-to-edge repair] and may expand treatment options for these patients,” although the outcomes did not appear quite as good as in the population in the main trial, he concluded.

However, the definition of anatomical complexity “you’re showing is not only old, it’s actually outdated,” argued Asch. “What we considered complex more than 15 years ago at this point when EVEREST was designed and reported and even COAPT as such, it’s not as complex as thought before.

“Maybe we improved with our technique, maybe devices improved, maybe not as afraid of them anymore. … So maybe we need to change our thresholds for these different criteria for [complexity],” I stated.

Disclosures

The CLASP IID trial was funded by Edwards Lifesciences.

Lim disclosed relationships with, and/or support from, Philips, Venus, Valgen, Abbott, Boston Scientific, Edwards Lifesciences, and Medtronic.

Prendergast disclosed relationships with Edwards Lifesciences, Abbott Vascular, and Medtronic.

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