Bailout valve-in-valve therapy during transcatheter aortic valve replacement in bicuspid and tricuspid aortic stenosis: an observational single-centre study in China.

BACKGROUND

Bailout valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) is a critical rescue strategy for procedural failure, yet evidence regarding its outcomes in bicuspid aortic valve (BAV) anatomy remains limited.

METHODS

This retrospective, single-centre study analysed 1597 patients (48.3% BAV) undergoing TAVR. Patients were stratified by the requirement for bailout ViV, which was conducted for significant residual aortic regurgitation (AR) or valve embolisation. Predictors were identified via multivariate logistic regression. Early- and mid-term survival outcomes were compared using Inverse Probability of Treatment Weighting (IPTW) via entropy balancing.

RESULTS

Bailout ViV was required in 6.20% of patients (BAV: 6.87%; tricuspid aortic valve (TAV): 5.57%). Larger annulus perimeter and significant residual AR after initial deployment were identified as consistent independent predictors of bailout ViV across all cohorts. Additionally, lower annulus calcification volume, non-repositionable self-expanding valves and the learning phase were predictors in the overall cohort. Significant mitral regurgitation and lower calcification volume in BAV and male sex in TAV cohorts were independent risk factors. IPTW-adjusted analysis revealed significantly higher 30-day all-cause (HR 3.09, p=0.019) and cardiovascular mortality (HR 3.49, p=0.021) in the bailout ViV group. However, no significant differences were observed in mid-term all-cause or cardiovascular mortality between groups.

CONCLUSIONS

Bailout ViV was associated with elevated early mortality but offered satisfactory mid-term survival. Key predictors include anatomical challenges (large annulus and insufficient calcification) and procedural factors (non-repositionable self-expanding valve, learning phase TAVR and significant residual AR after the first prosthesis).