Impact of conduction disturbances persistency on 2-year outcomes after transcatheter aortic valve implantation

Background Conduction disturbances (CD) can be present before transcatheter aortic valve implantation (TAVI) or develop after TAVI, manifesting as either transient or persistent, and be associated with poor prognosis in patients with aortic stenosis (AS). However, definitions of CD have varied across previous studies, complicating the assessment of CD. Moreover, the difference in prognostic impact between transient and persistent CD has not been well investigated. Purpose This study aimed to classify patients by timing and persistency of CD and evaluate their impact on clinical outcomes in AS patients undergoing TAVI. Methods Patients with AS who underwent TAVI at two centers between August 2016 and June 2024 were enrolled in this study. CD was defined as left or right bundle branch block, significant intraventricular conduction delay with QRS interval ≥ 120 ms, any complete atrioventricular block, or any pacemaker implantation. Clinical outcomes were first compared between patients with and without pre-existing CD, and then, patients without pre-existing CD were further categorized into 3 groups: transient CD, persistent CD, or no CD (Figure 1). Transient CD was defined as post-TAVI CD that resolved before discharge or within 7 days after TAVI, whereas persistent CD remained at discharge or beyond 7 days after TAVI. The primary endpoint was a composite of cardiovascular death or heart failure rehospitalization. Results Among 940 patients, 217 (23.1%) had pre-existing CD. The incidence of the primary endpoint at 2 years after TAVI was similar between patients with and without pre-existing CD (9.7% vs 9.4%; log-rank p=0.999; Figure 2). In 723 patients without pre-existing CD, 108 (14.9%) had persistent CD, 146 (20.2%) had transient CD, and 469 (64.9%) had no CD. At 2 years, the primary endpoint occurred more frequently in patients with persistent CD than in those with transient or no CD (17.6% vs. 8.2% vs. 7.9%, respectively; log-rank p=0.029; Figure 2). No significant difference was observed between the transient and no CD groups. Conclusions In this study, pre-existing CD was not associated with adverse outcomes in AS patients undergoing TAVI. In patients without pre-existing CD, persistent CD was linked to a worse prognosis compared to transient or no CD. Therefore, persistent CD should be carefully considered in post-TAVI risk stratification.