Early Studies Suggest Lasting Benefits From Percutaneous Fix for Functional Mitral Regurgitation

Catheter-based direct annuloplasty to treat functional mitral regurgitation (MR) is feasible and has durable effects on MR severity and functional outcomes 6 months to a year after implantation, according to 2 studies of the Cardioband system presented April 23 and 24, 2015, at the American Society for Thoracic Surgery’s Mitral Conclave in New York, NY.

“This first-in-man experience is a milestone accomplishment by a very experienced group,” Isaac George, MD, of Columbia University Medical Center (New York, NY), told TCTMD in an email. “The technology is the most mature of potentially a number of exciting transcatheter devices aimed at securing and reducing annular dimensions.

“These abstracts definitively show that the procedure is technically feasible and patients derive symptomatic benefit from it at least to 6 months,” he said.

The first study, a first-in-human experience presented by Francesco Maisano, MD, of University Hospital Zurich (Zurich, Switzerland), included 35 high-risk patients with significant functional MR (mean age 72 years; 80% men) who were treated at 6 European sites with the Cardioband percutaneous annuloplasty system (Valtech Cardio; Or Yehuda, Israel), an adjustable, “surgical-like” ring delivered via the transseptal approach.

At baseline, the median Society of Thoracic Surgeons score was 7%, mean ejection fraction was 35%, and 94% of patients were in NYHA class III/IV.

Implantation of the device was feasible in all patients, and acute procedural success—defined as successful implantation with an acute reduction of MR to less than 2+—was achieved in all but 2. Cinching of the device resulted in an average 22% reduction of the septolateral diameter (from 36 to 29 mm; P < .01). By 30 days, 2 patients had died: 1 from hemorrhagic stroke and 1 following an elective mitral operation.

At 6 months, 80% of patients were in NYHA class I/II and self-reported quality of life had improved, with the Minnesota Living With Heart Failure questionnaire score dropping from 40 at baseline to 18 at the final follow-up (P < .05). The percentage of patients with MR ≤ 2 was 85% at 6 months and 90% at 1 year.

Potential Longer-Term Gains Seen

The second study, presented by Yan Topilsky, MD, of Tel Aviv Medical Center (Tel Aviv, Israel), provided outcomes 1 year after implantation of the Cardioband system in 6 patients with moderate-to-severe functional MR and baseline characteristics “worse than what is considered to support remodeling for surgical mitral repair in functional MR patients,” Dr. Maisano—a coauthor of the study—told TCTMD in an email.

Median MR grade declined from 3.5 to 1 during follow-up (P = .002), regardless of baseline valvular alterations, LV size, or sphericity. There also were reductions in median annular diameter, tenting area, and LV end-diastolic diameter and a nonsignificant trend toward a decrease in anterior leaflet angle (table 1).

Implantation of the device did not affect tenting height, posterior leaflet angle, interpapillary muscle distance, or sphericity index.

The observed ventricular and valvular changes were accompanied by improved symptoms and function. Median NYHA class fell from III to II, and mean 6-minute walk distance lengthened from 302 to 499 meters (P = .04 for both).

Uncertainty About Place in Clinical Practice

According to Dr. George, the second study shows that the procedure “likely produce[s] hemodynamic and geometric results similar to a surgical annuloplasty, on which it is based.”

But, “where this procedure will fit in the pantheon of treatment for functional MR remains to be seen,” he added. “Surgical results for functional MR have been disappointing, highlighted by the recent CTSN randomized trial showing recurrence of MR in up to a third of patients at 1 year compared to valve replacement in ischemic MR.”

Moving forward, “it will be very important to demonstrate longer-term efficacy without the failure mode and rates that are seen with repair surgery [in order] for this technology to be applicable outside of the extremely sick, inoperable heart failure patients with no option in whom durability is not a concern,” Dr. George said. He also noted that the lack of changes in sphericity and interpapillary muscle distance are “reflective of the ongoing ventricular remodeling that may lead to late MR recurrence.”

“If benefits can be shown that are equal or beyond surgery at a fraction of the risk,” he added, “[the transcatheter approach] has the potential to revolutionize how we treat functional MR.”

Dr. Maisano said the approach “has the potential to become the first-line option in patients with functional MR.” He noted that it does not need to be accompanied by long-term anticoagulation and does not preclude further interventions.

Concerns Remain

Dr. George expressed concern about how the procedure would be performed by less-experienced operators and centers. “It seems to be a technically difficult procedure to master and will require a high level of imaging expertise that centers may not possess,” he said. “Regardless, it is very encouraging to see these procedures being performed from a transseptal route rather than a transapical route, which we know confers a sizable risk in terms of recovery from our TAVR experience.”

Other unanswered questions deal with the level of procedural risk that can be tolerated by patients with MR, whether replacement is better than annular stabilization, how much the ventricle contributes to late failure, and the timing of treatment, Dr. George said.

Sources:
1. Maisano F. Catheter-based direct annuloplasty: results from multicenter first-in-man feasibility trial. Presented at: AATS Mitral Conclave; April 23, 2015; New York, NY.
2. Topilsky Y. Percutaneous annuloplasty successfully treats type IIIb mitral regurgitation. Presented at: AATS Mitral Conclave; April 24, 2015; New York, NY.

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