TAV-in-BAV: TAVR Achieves Positive Outcomes In Bicuspid Aortic Valve Disease

WASHINGTON, DC—Transcatheter aortic valve replacement (TAVR) appears to be a safe, effective option for high-risk patients with bicuspid aortic valve (BAV) disease, which occurs in 0.5% to 2% of the general population and is a common indication for surgical aortic valve replacement (SAVR) in younger adults, according to findings  presented March 30, 2014, at the American College of Cardiology/i2 Scientific Session.

Researchers led by Darren Mylotte, MD, of McGill University Health Center (Montreal, Canada), looked at 143 patients who underwent TAVR for  BAV disease at 12 Canadian and European centers.

TAVR implants included the Sapien (Edwards Lifesciences, n = 51), the CoreValve (Medtronic, n = 91), and the Lotus prosthesis (Boston Scientific, n = 1). CoreValve devices used in the study had larger mean sizes and were more often deployed through femoral access, CT-based valve sizing was used in more than half of all patients, especially those who received Sapien valves (table 1).

Table 1. Procedural Data

On postimplantation echocardiography, roughly one-third of all patients (33.3%) had aortic regurgitation grade 2 or 3. On multivariable analysis, male sex was an independent predictor of aortic regurgitation (AR) grade 2 or more (OR 4.22; 95% CI 1.62-10.98; P = 0.003), while CT-based sizing was a predictor of lower likelihood of AR grade 2 or higher (OR 0.17; 95% CI 0.05-0.53; P = 0.002).

Overall mortality was 4.9% at 30 days, 9.3% at 6 months and 15.9% at 1 year. Mortality did not differ according to valve type, although minor bleeding was more common with CoreValve than with Sapien (17.6% vs 2.0%; P = 0.02).

Borderline predictors of worse 1-year survival included CoreValve (OR 0.45; 95% CI 0.16-0.99; P = 0.05) and valve embolization (OR 5.70; 95% CI 0.99-32.72; P = 0.052).

“In high-risk patients with significant BAV disease, TAV-in-BAV appears to be a safe and effective approach,” Dr. Mylotte concluded. “Short and intermediate-term clinical outcomes are encouraging, though there appears to be a [slightly] high incidence of postimplantation aortic regurgitation in these patients.” He continued that CT-based sizing should be routinely used, and that longer follow-up of larger populations is needed to more completely assess TAV-in-BAV.

TAV-in-BAV Normally Contraindicated

To date, transcatheter valves have been relatively ontraindicated in patients with BAV disease. “The main reason is the morphology of the valve is extremely different,” Dr. Mylotte said. “The way the valve fails is extremely different. It’s more complex with a high rate of calcification, and the asymmetric pattern of calcification can distort the transcatheter valve and make these procedures more challenging and complex.”

However, Dr. Mylotte added, “If the data that has been emerging and the incidence of bicuspid valve disease , transcatheter valves will have an impact in this area.”

Panel comoderator Jeffrey S. Borer, MD, of State University of New York (SUNY) Downstate Medical Center (Brooklyn, NY), noted that due to the way the primary TAVR device was approved in the United States, “it would be very difficult to perform the procedure in somebody with a bicuspid aortic valve.” Regarding the study, he observed, “Outcomes were good except for the aortic regurgitation. I wonder whether the patients were truly not candidates for conventional surgery, which is quite successful for patients with bicuspid aortic valve. Were these really people who could not have conventional surgery?”

Dr. Mylotte responded that there are experienced heart teams at each participating center, “and they felt  it best to proceed with a transcatheter valve,” he said. “In terms of should we treat patients with this technology, I think most centers that do enough TAVR are already treating patients with this technology whether they know it or not. I think many of us certainly have treated patients and have realized afterward that the valve was actually bicuspid.”

Dr. Borer wondered how the relatively high residual rate of AR should be handled in the future.

“I think the use of CT sizing is absolutely critical in reducing the rates of bivalve  regurgitation,” Dr. Mylotte responded. “That’s probably the most important factor.”

Study Details

The average age of the patients was 77.7 years, and more than half (57.3%) were male. The majority (82.5%) were in NYHA class 3 or 4.

Source:
Mylotte D. Transcatheter aortic valve replacement in bicuspid aortic valve disease. Presented at the American College of Cardiology (ACC)/i2 Scientific Session; March 30, 2014; Washington, DC.

Disclosures:

• Dr. Mylotte reports no relevant conflicts of interest.

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