New-Onset RBBB After Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation

Background: In contrast to left bundle branch block, right bundle branch block (RBBB) is rare after transcatheter aortic valve replacement (TAVR). Objectives: This study sought to define the incidence of post-TAVR new-onset RBBB and the risk factors associated with permanent pacemaker implantation (PPI) need. Methods: Data from 7,782 consecutive TAVR procedures performed in 7 Israeli centers were retrospectively analyzed. A baseline electrocardiogram was performed within 2 days before TAVR and daily thereafter. Absolute pacing indication (API) was defined as the occurrence of high-grade atrioventricular block or alternating bundle branch block. Results: Overall, 41 patients with new-onset RBBB were identified, translating into an incidence of 5.3 (95% CI: 3.8-7.1) cases per 1,000 TAVR procedures. During 1 year post-TAVR, 19 patients (46.3%) underwent PPI, of whom 15 (36.6%) had API. All API occurred before discharge from the index TAVR hospitalization except in 1 case of late atrioventricular block. A cutoff of post-TAVR PR of 228 ms had a specificity of 95% and a sensitivity of 50% in predicting API, whereas Δ PR of 24 ms had a specificity of 80% and a sensitivity of 83% in predicting API. Patients who did not undergo PPI had a nonsignificantly better overall survival compared with patients with PPI. Conclusions: Post-TAVR new-onset RBBB is a rare phenomenon that is associated with high rates of further conduction system deterioration and need for PPI, occurring mostly within 1 week post-TAVR. Post-TAVR PR ≥230 ms and Δ PR ≥24 ms, vs post-TAVR PR <230 ms and unchanged PR, may help stratifying the patients into high and relatively low risk of progressive conduction worsening, respectively.