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Bicuspid Anatomy Not Necessarily a Disadvantage for TAVR

— Do these registry findings warrant a randomized trial?

MedpageToday

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NEW ORLEANS -- A bicuspid aortic valve (BAV) didn't stop some patients from getting transcatheter aortic valve replacement (TAVR) for aortic stenosis and faring well afterward, data from the TVT Registry showed.

Sapien 3 recipients with BAV anatomy had similar adjusted 1-year event rates when matched to peers with tricuspid aortic valves also getting TAVR:

  • Mortality (10.5% vs 12.0%, P=0.31)
  • Stroke rates (3.4% vs 3.1%, P=0.16)
  • Mortality or stroke (12.9% vs 14.1%, P=0.75)

"This analysis suggests that bicuspid anatomy is amenable to TAVR with current generation balloon-expandable TAVR technology with acceptable clinical outcomes," investigator Raj Makkar, MD, of Cedars-Sinai Medical Center in Los Angeles, told the audience here at the annual meeting of the (ACC).

"These data provide an argument for TAVR to be a reasonable alternative for bicuspid AS [aortic stenosis] in patients who are intermediate or high risk for surgical aortic valve replacement and provide a sound basis to conduct a randomized clinical trial in young patients with bicuspid AS who are low risk for surgery," he continued.

Low-risk patients had just been shown to derive the same benefits of TAVR as peers getting surgery in the PARTNER 3 and CoreValve Low Risk trials presented during the same ACC late-breaking trial session.

Patients with BAV had been excluded from these and other major TAVR trials.

"I think it's very hard seeing the data being presented and the data that you just presented to take an even intermediate-risk surgical patient just because they were bicuspid and not do TAVR. I think that will be very hard to swallow," commented panelist Blase Carabello, MD, of the East Carolina Heart Institute at Vidant Medical Center in Greenville, North Carolina.

Anatomical risk stratification was not covered by the BAV analysis, Makkar cautioned in response, leading Carabello to agree: "All bicuspid valves are not created equal."

Makkar's study was based on TAVR patients in the TVT registry who had tricuspid anatomy (n=79,096) and bicuspid anatomy (n=2,726).

Only 5% or less of patients in the registry received embolic protection during TAVR as the first two-thirds of patients were enrolled during a time when these devices were not available, the researcher noted.

"Based on these data, it would be wise for us to use cerebral protection devices especially when we are doing TAVR in patients who have bicuspid aortic stenosis, because these valves tend to be more heavily calcified than [in] tricuspid aortic stenosis," according to Makkar.

At baseline, BAV patients comprised a younger cohort with a lesser comorbidity burden and lower surgical risk. They had larger annuli (average 25.08 mm vs 24.63 mm, P<0.0001), so they tended to get larger valves.

During the procedure, this group had more conversion to open surgery (0.9% vs 0.4%, P=0.03) and annulus rupture (0.3% vs 0%, P=0.02), but no greater need for a second valve (0.4% vs 0.2%, P=0.16).

Without adjustment, stroke but not mortality was elevated among the BAV group at 30 days (2.4% vs 1.6%, P=0.02), and the rate of new pacemakers was also higher in these patients (9.1% vs 7.5%, P=0.03). At 1 year, their unadjusted rate of mortality was actually lower than those with tricuspid anatomy (10.4% vs 14.4%, log-rank P<0.001), whereas the incidence of stroke was similar.

After matching, echocardiography showed no difference in paravalvular leak, mean gradient, and aortic valve area between groups at discharge, 30 days, and 1 year.

Bicuspid and tricuspid patients also shared similar quality-of-life metrics throughout follow-up, namely, New York Heart Association classification and Kansas City Cardiomyopathy Questionnaire overall summary scores.

The analysis suffered from the lack of independent adverse event adjudication and the possibility that operators chose only the most favorable BAV patients for TAVR, Makkar acknowledged.

It's important to note that the patients in this analysis did not have aortopathy, said Chadi Alraies, MD, MPH, of Wayne State University and Detroit Medical Center, who was not part of Makkar's research group.

"It's interesting that the findings in low-risk TAVR and this analysis are consistent, showing favorable outcomes toward TAVR to surgery. However, given the age of the patients being younger, durability is still a concern. There are multiple registries in Europe showing TAVR can be durable at 5 years, but we don't know beyond that," he said in an interview.

TAVR can be presented as an option in a serious discussion with BAV patients -- but Makkar's findings cannot be implemented yet as there is significant heterogeneity within the BAV population due to differing hemodynamics and morphologies, Alraies said.

  • author['full_name']

    Nicole Lou is a reporter for ֱ, where she covers cardiology news and other developments in medicine.

Disclosures

Makkar disclosed grants and/or personal fees from Edwards Lifesciences, Abbott, Medtronic, and Boston Scientific; and holding stock/equity in Entourage Medical.

Primary Source

American College of Cardiology

Makkar RR, et al "Outcomes of transcatheter aortic valve replacement with balloon-expandable Sapien 3 valve in bicuspid aortic stenosis: an analysis of the STS/ACC TVT Registry" ACC 2019.