Transcatheter Aortic Valve Replacement With Balloon- Versus Self-Expandable Bioprostheses for the Treatment of Bicuspid Aortic Valve Stenosis

BACKGROUND: Differences between balloon- and self-expandable transcatheter heart valves (BE-THVs and SE-THVs, respectively) may influence the outcomes of transcatheter aortic valve replacement for bicuspid aortic valve (BAV) stenosis. METHODS: Consecutive patients undergoing transcatheter aortic valve replacement with BE-THV or SE-THV for computed tomography-diagnosed bicuspid aortic valve stenosis at 29 centers were included. The primary outcome was death or stroke. After propensity score matching in 10 data sets generated by multiple imputation, outcomes from transcatheter aortic valve replacement to 3-year follow-up were computed by multivariable binomial logistic mixed-effects models, multivariable linear mixed-effects models, or multivariable frailty models accounting for center-related influences and residual confounding effects (doubly robust adjustment). The results were replicated by inverse probability of treatment weighting and multivariable adjustment. RESULTS: A total of 1443 consecutive patients with bicuspid aortic valve stenosis undergoing BE-THV (n=860) or SE-THV (n=583) implantation were included. In-hospital and 30-day death or stroke did not significantly differ between BE-THV and SE-THV groups (5.1% versus 6.1%; hazard ratio after propensity score matching, 1.02 [95% CI, 0.51-2.02]). BE-THV implantation was associated with higher annulus rupture and mean transvalvular gradient compared with SE-THV implantation. In contrast, SE-THV implantation was associated with higher additional valve implantation and paravalvular regurgitation compared with BE-THV implantation. The results were consistent across the statistical methods used and between early- and new-generation THVs. At 30 days, pacemaker implantation was lower in the BE-THV group compared with the SE-THV group (11.9% versus 18.6%; hazard ratio after propensity score matching, 0.58 [95% CI, 0.36-0.93]). This result did not depend on the statistical method used. At 3 years, consistent with the 1- and 2-year analyses, death or stroke was not significantly different between the BE-THV and SE-THV groups (23.7% versus 26.2%; hazard ratio after propensity score matching, 0.99 [95% CI, 0.65-1.51]). Death or stroke across major clinical, anatomical, functional, and procedural conditions was consistent with the main analysis. After inverse probability of treatment weighting and multivariable adjustment, these conclusions remained unchanged. CONCLUSIONS: In patients undergoing transcatheter aortic valve replacement for bicuspid aortic valve stenosis, death or stroke does not significantly differ between those receiving a BE-THV and those receiving an SE-THV over a follow-up of 3 years. BE-THV is associated with higher transvalvular mean gradient and more frequent annulus rupture, whereas SE-THV is associated with more frequent moderate to severe aortic regurgitation, additional THV implantation, and permanent pacemaker implantation.