Predictors of conduction disturbances after transcatheter aortic valve implantation with balloon-expandable valve for bicuspid aortic valve stenosis

Introduction: Implantation depth and membranous septum (MS) length have been established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV.

Methods: This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoints were in-hospital new permanent pacemaker implantation (PPI) and new-onset CD (the composite outcome of new-onset left bundle branch block and new PPI).

Results: PPI developed in 14 patients (8.3%) and new-onset CD in 37 patients (21.9%) in the BAV cohort. Multivariate analysis revealed severe left ventricle outflow tract (LVOT) calcification (odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08-31.5, p = .0407) and implantation depth-MS length (OR: 1.30, 95% CI: 1.12-1.51, p = .0005) as the predictors of new-onset CD within the BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs. 3.2 mm, p = .5307), but valves were implanted more deeply in the BAV group than in the TAV group (3.9 vs. 3.0 mm, p < .0001). New-onset CD was more frequent in patients who had BAV (22.3% vs. 13.9%, p = .0458).

Conclusion: The implantation depth-MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. Among BAV patients, valves were implanted more deeply compared to TAV patients. High deployment technique could be considered to avoid new-onset CD in BAV anatomy.