CT-derived basal interventricular septal thickness < 4.35 mm independently predicted permanent pacemaker implantation within 1 month post-TAVR (adjusted OR 0.05; 95% CI 0.01-0.32; P=0.002).
Observational (n=66)
Does pre-procedural CT-derived basal interventricular septal thickness predict permanent pacemaker implantation within 1 month post-TAVR in patients with preexisting right bundle branch block?
Pre-procedural CT measurement of basal septal thickness improves risk stratification for permanent pacemaker implantation after TAVR in high-risk patients with preexisting RBBB.
Effect estimate: adjusted OR 0.05 (95% CI 0.01-0.32)
p-value: p=0.002
• CT-measured basal septal thickness independently predicts post-TAVR pacemaker need in patients with pre-existing right bundle branch block. • A cutoff of < 4.35 mm at 2 mm below the membranous septum provides optimal discrimination (AUC 0.91). • Thinner septum and deeper valve implantation jointly increase pacing risk. • Integration of septal thickness improves risk stratification beyond conventional predictors. • Findings support the role of septal anatomy in protecting the conduction system during TAVR. Conduction disturbances requiring permanent pacemaker implantation (PPI) remain common after transcatheter aortic valve replacement (TAVR). This study evaluated whether pre-procedural CT-derived basal muscular interventricular septal (IVS) thickness predicts PPI within 1 month post-TAVR in patients with preexisting right bundle branch block (RBBB). In 66 TAVR patients with severe aortic stenosis and preexisting RBBB, IVS thickness was measured at 2, 4, 6 and 8 mm below the membranous septum (MS) on CT coronal views. Univariate /multivariate logistic regression were used to identify predictors, and receiver operating characteristic (ROC) analysis evaluated predictive performance. PPI was required in 28 patients (42.4%). The PPI group exhibited significantly thinner IVS across all measured levels (all P < 0.05). Univariate analysis revealed that every 1-mm increase in IVS thickness at 2 mm below MS, the risk of PPI was markedly reduced (OR 0.003, 95% CI: 0.001–0.059). Multivariate analysis adjusting for age, implantation depth, and membranous septum length (MSL) confirmed that IVS thickness < 4.35 mm at 2 mm below MS (adjusted OR 0.05, 95% CI: 0.01–0.32, P = 0.002) and lower MSL–implantation depth difference (MSL-ID) were independent predictors of PPI. The model incorporating IVS thickness showed excellent discrimination (AUC 0.91, 95% CI: 0.84–0.98), superior to the model without it (AUC 0.82, 95% CI: 0.71–0.92). Pre-procedural CT-derived basal IVS thickness independently predicts post-TAVR PPI in patients with preexisting RBBB. Thinner IVS may reflect less anatomical protection for the conduction system during valve deployment. Integrating IVS thickness into risk assessment could improve patient stratification and procedural planning.
Li et al. (Tue,) conducted a observational in Severe aortic stenosis with preexisting right bundle branch block (n=66). CT-derived basal interventricular septal thickness was evaluated on Permanent pacemaker implantation (PPI) within 1 month post-TAVR (adjusted OR 0.05, 95% CI 0.01-0.32, p=0.002). CT-derived basal interventricular septal thickness < 4.35 mm independently predicted permanent pacemaker implantation within 1 month post-TAVR (adjusted OR 0.05; 95% CI 0.01-0.32; P=0.002).