TAVR With Sapien 3 Requires Less Zealous Oversizing

The third-generation Sapien 3 device for transcatheter aortic valve replacement (TAVR) requires just minimal oversizing to ensure adequate anchoring while avoiding aortic root ruptures, according to a registry of PARTNER II participants.

Moderate or worse paravalvular aortic regurgitation occurred in 3.6% of patients in the analysis. Unsurprisingly, the highest degrees of CT-guided oversizing were tied to the lowest odds of paravalvular aortic regurgitation at 30 days. For example, oversizing the area by 10% or more was tied to an infrequent 0.3% rate of moderate-or-worse regurgitation, according to Jonathon Leipsic, MD, of St. Paul's Hospital in Vancouver, Canada, and colleagues.

Even so, oversizing just up to 5% by area and perimeter were associated with "acceptable" regurgitation rates under 3%, the investigators reported in JACC: Cardiovascular Interventions. There were no aortic root ruptures observed in the registry.

Although this device "allows for overall reduced rates of moderate or severe paravalvular aortic regurgitation, the most important finding in regard to device sizing is the ability to minimally oversize the native aortic annulus or modest undersizing while maintaining these low rates and more modest severity of paravalvular aortic regurgitation," Leipsic's group commented.

The Sapien 3 offers a chance to reduce the risk of annular rupture associated with more aggressive oversizing (approaching 20%), they added.

"This allows for a paradigm shift regarding device selection for balloon-expandable TAVR in borderline anatomy: cases that previously were approached by oversizing the device but implanting with balloon-underfilling may now be treated by full expansion of a smaller device. Preventing aggressive oversizing by means of selecting a smaller device (i.e., undersizing) in borderline anatomy has the potential to significantly reduce the risk of rupture associated with significant oversizing with a balloon-expandable TAVR."

"This study confirms that the few remaining issues with TAVR are slowly but surely being resolved, boosting the momentum of this transformative therapy," said Mohamed Alkhouli, MD, and colleagues at the West Virginia University Heart & Vascular Institute in Morgantown, in an accompanying editorial.

"This degree of oversizing is significantly less than the >10% oversizing required to achieve comparably low rates of paravalvular aortic regurgitation with the earlier generation Sapien XT valve. This is likely due to distinctive features of the newer generation S3 valve," the editorialists wrote, such as the new frame design and the addition of an outer sealing cuff.

Data for the current study came from a multicenter registry spanning the U.S. and Canada. Restricting analysis to intermediate-risk patients who underwent successful Sapien 3 placement and had systolic aortic annular dimensions on CT and echocardiographic grading of post-implant paravalvular aortic regurgitation, his group ended up with 835 individuals with severe, symptomatic aortic stenosis for the study.

Average age was 82.1 and STS score 5.27%. Men comprised 61.4% of the study group.

CT-based oversizing reached a mean of 7.7% by area and 1.7% by perimeter.

Perimeter and area oversizing shared similar predictive capacities for paravalvular aortic regurgitation after Sapien 3 implantation (AUC 0.78, 95% CI 0.70-0.85; and AUC 0.78, 95% CI 0.72-0.85).

Among the study limitations were the lack of core lab adjudication on the level of valve implantation; missing post-implant imaging; and the exclusion of patients with bicuspid valve morphology.