The Incidence, Predictors and Implications of Cardiac Conduction Abnormalities Following Transcatheter Aortic Valve Implantation (TAVI) to Treat Aortic Stenosis

Abstract

Transcatheter aortic valve implantation (TAVI) is an established and effective therapy for severe aortic stenosis. Despite advances in valve technology and implantation techniques, conduction disturbances remain frequently, and clinically consequential. This thesis aims to define the incidence, timing, and predictors of post-TAVI conduction disease, with a focus on high-grade atrioventricular block (HGAVB) requiring permanent pacemaker implantation (PPMI). Secondary objectives include evaluating the natural history and prognostic significance of new bundle branch block and new-onset atrial fibrillation (NOAF), as well as assessing implications on contemporary TAVI care pathways and lifetime management.

Combining retrospective analyses and a rigorously monitored prospective cohort incorporating extended continuous rhythm surveillance (the CONDUCT-TAVI study), this thesis demonstrates that the true incidence cardiac conduction disorders after TAVI is substantially underestimated with routine follow-up. CONDUCT-TAVI further demonstrates that key independent predictors are derived from electrophysiological assessment, including baseline right bundle branch block, dynamic changes in the His–ventricular interval, and pacing-induced atrioventricular conduction delay. In parallel, refined computed tomography–based anatomical assessment, including cardiac phase-specific and three-dimensional characterisation of the conduction system, enhances non-invasive risk prediction.

This thesis further introduces pragmatic risk-stratification tools and care pathways, including algorithms supporting same-day discharge in select low-risk patients, potentially improving patient experience, hospital efficiency, and healthcare costs. Broader considerations relating to lifetime care and future valve-in-valve feasibility are also explored, highlighting the expanding role of TAVI in younger populations.