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

In contrast to left bundle branch block, right bundle branch block (RBBB) is rare after transcatheter aortic valve replacement (TAVR).

This study sought to define the incidence of post-TAVR new-onset RBBB and the risk factors associated with permanent pacemaker implantation (PPI) need.

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.

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.

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.