PASCAL for MV Repair Noninferior to MitraClip in CLASP IID, FDA Took Notice

September 17, 2022

A newly available transcatheter device for edge-to-edge mitral valve (MV) repair, named for a famed scientist-inventor, is similar to the long-available MitraClip (Abbott) for short-term efficacy and safety, suggests an interim but prespecified analysis from a randomized trial.

In its comparison with MitraClip, the PASCAL transcatheter valve repair system (Edwards Lifesciences) was noninferior with respect to 30-day major adverse events and to success at achieving mitral regurgitation (MR) of no more than moderate severity within 6 months. The trial had entered patients with significant, symptomatic degenerative MR considered too high-risk for surgical repair or replacement.

The interim analysis covers 180 of the 300 patients followed in the study, of whom 117 received the PASCAL device and 63 were given MitraClip. Both groups showed significant gains in functional class, symptom status, and quality of life over 6 months, reported D. Scott Lim, MD, University of Virginia Health System Hospital, Charlottesville, and Konstantinos Koulogiannis, MD, Morristown Medical Center, New Jersey, jointly on September 17 at Transcatheter Cardiovascular Therapeutics (TCT) 2022 in Boston, Massachusetts.

Lim, one of the trial's principal investigators, is also lead author on its same-day publication in JACC: Cardiovascular Interventions.

Based largely on those results from the CLASP IID pivotal trial, the U.S. Food and Drug Administration (FDA) recently approved the PASCAL system for use in patients with degenerative MR, Edwards announced on September 15. The device was approved in the European Union on August 17.

MitraClip has been available in various iterations in the United States since 2013 and in Europe since 2008.

"It's good for the field to be able to say we have two devices that are comparable," giving clinicians more options, Vinod H. Thourani, MD, Piedmont Heart Institute, Atlanta, Georgia, told | Medscape Cardiology.

The current analysis shows that "we've yet to figure out what patient pathologies will be beneficial" for each of the devices, Thourani said. "The goal will be to find out if there are certain anatomical considerations where one device is better than the other."

It will be necessary to study "more patients, a larger cohort, with longer follow-up to allow us to see their true benefits," he said, as well as to conduct more subgroup analyses. For now, the choice of device will probably be "operator-specific, which they feel comfortable with."

Thourani, not an author on the current study, is the U.S. principal investigator for the CLASP IIF study looking at clinical outcomes with the two devices and says he consults for both Edwards and Abbott.

The findings are "preliminary for now," said Michael Young, MD, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, in part because, like most randomized trials, CLASP IID entered a select, not broadly representative population.

"They want to make, as best as they could, an apples-to-apples comparison, without confounding that might make it more difficult to interpret it afterwards," Young, not associated with the trial, told | Medscape Cardiology.

But CLASP IID "did enroll patients that we do see and treat, so undoubtedly it's a compelling study. We now have another device that is shown to be safe and effective. How we're going to extrapolate it to all the patients that are being referred to our practices will, I think, be under debate and deliberation."

The PASCAL and MitraClip devices each may be more suitable for different patients with varying mitral valve pathologies due to differences in their designs, Lim said. The PASCAL's relative flexibility might make it preferable in patients with smaller mitral valves, and its ability to elongate during delivery could make it more suitable for patients with chordal-dense areas around the valve, he speculated.

MitraClip, Lim told | Medscape Cardiology, has a mechanical closure system for anchoring that may make it more appropriate for "more complicated, thicker leaflets with calcium."

CLASP IID enrolled patients with grade 3+ or 4+ degenerative MR considered to be "at prohibitive surgical risk" at 43 sites in North America and Europe. It randomly assigned them 2-to-1 to receive the PASCAL device or MitraClip.

Either of two PASCAL versions were used, the original device or the "smaller, narrower" PASCAL Ace, Lim observed. Both versions are covered by the PASCAL Precision System FDA approval. About 40% of patients assigned to MitraClip received older versions of the device and about 60%, more recent versions, as they were entered into practice.

The mean procedure times were 88 minutes for PASCAL and 79 minutes for MitraClip (P = .023), with much of the difference attributable to the earliest PASCAL procedures. Procedure times for the device declined with greater operator experience, the published report states.

Rates of the primary safety endpoint of major adverse events at 30 days were 3.4% for PASCAL and 4.8% for MitraClip. The endpoint was a composite of cardiovascular  mortality, stroke, myocardial infarction, new need for renal replacement therapy, severe bleeding, or nonelective MV reintervention.

The proportion of patients with MR grade 2+ or lower at 6 months, the primary effectiveness endpoint, assessed at a core laboratory, was 96.5% for the PASCAL group over a median follow-up of 179.5 days and 96.8% over a median of 184.5 days for those who received MitraClip.

Comparisons for both primary endpoints met the prespecified criteria for PASCAL noninferiority.

In a secondary analysis, the proportion of PASCAL patients with MR grade 1+ or less held about steady from postprocedure discharge out to 6 months, at 87.2% and 83.7%, respectively (P = .317).

But  whereas 88.5% of MitraClip patients had MR grade 1+ or better at discharge, 71.2% were at that grade by 6 months (P = .003). That apparent hemodynamic deterioration raised some eyebrows at the TCT sessions as a potential sign that PASCAL functional results are more durable.

That sort of judgment is premature, offered Anita W. Asgar, MD, MSc, Montreal Heart Institute, Quebec, Canada, as an invited discussant after the CLASP IID trial's formal presentation.

The trial is notable in part for "showing how safe this procedure is and how successful it is for these patients — this is phenomenal," she said, but  "I would caution comparing one device being better than another with such a small number of patients."

MitraClip, Young observed, "has been, up to this point, our only option for edge-to-edge repair of the mitral valve. And many of us have years of experience and a lot of patients that we treat with that device." His center hasn't yet used PASCAL, but that may change as the field gains more familiarity with the device. Operators may  use either device in different cases, he said.

"Depending on the program, and depending on the volume of mitral patients that you see and edge-to-edge repair that you do, it could be that you stick with one, or switch to another, or you integrate both of them and try to decide which patients might be better suited for one or the other."

CLASP IID was sponsored by Edwards Lifesciences. Lim discloses consulting for Philips, Venus, and Valgen  and receiving research grants from Abbott, Boston Scientific, Edwards Lifesciences, and Medtronic. Koulogiannis discloses consulting and serving on an advisory board for Edwards Lifesciences and as a speaker for Abbott and discloses holding equity, stocks, or stock options in 4C. Disclosures for the other authors are in the report. Thourani discloses serving as a consultant to both Abbott and Edwards Lifesciences. Young discloses receiving consulting fees or honoraria or serving on a speaker's bureau for Medtronic. Asgar discloses receiving research support from or holding a research contract with Abbott Vascular and receiving consulting fees or honoraria or serving on a speaker's bureau for Medtronic, Edwards Lifesciences, and W. Gore & Associates.

Transcatheter Cardiovascular Therapeutics (TCT) 2022. Presented September 17, 2022.

JACC Cardiovasc Intervent. Published online September 17, 2022. Abstract

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