Impact of New-Onset Left Bundle Branch Block and Periprocedural Permanent Pacemaker Implantation on Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is now an established treatment option for patients with aortic stenosis who are considered to be at high or prohibitive surgical risk. Substantial improvements in technology, patient selection, and refined procedural techniques have provided the basis for TAVRs expansion toward treating a lower surgical risk aortic stenosis population. However, the ocurrence of some periprocedural complications remain a concern. Conduction disturbances and the need for permanent pacemaker implantation (PPI) frequently complicate TAVR. Importantly, the incidence of such complications has not changed significantly over time, with potentially a slightly rising incidence after the introduction of newer generation transcatheter valves. Although the factors associated with conduction abnormalities and PPI post-TAVR are well described, data on its clinical impact remain controversial. Studies evaluating the impact on mortality of new-onset left bundle branch block (LBBB) or need for periprocedural PPI post-TAVR have yielded conflicting results. The current systematic review and meta-analysis was thus aimed at assessing (1) the impact of new-onset LBBB post-TAVR on the need for PPI, all-cause death, and cardiac death and (2) the impact of periprocedural PPI post-TAVR on all-cause and cardiac death. Background—Available data on the clinical impact of new-onset left bundle branch block (LBBB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR) remains controversial. We aimed to evaluate the impact of (1) periprocedural new-onset LBBB or PPI post-TAVR on cardiac mortality and all-cause 1-year mortality and (2) new-onset LBBB on the need for PPI at 1-year follow-up. Methods and Results—We performed a systematic search from PubMed and EMBASE databases for studies reporting raw data on new-onset LBBB post-TAVR and the need for PPI or mortality at 1-year follow-up, or on 1-year mortality according to the need for periprocedural PPI post-TAVR. Data from 17 studies, including 4756 patients (8 studies) and 7032 patients (11 studies) for the evaluation of the impact of new-onset LBBB and periprocedural PPI post-TAVR were sourced, respectively (with 2 studies used for both outcomes). New-onset LBBB post-TAVR was associated with a higher risk of PPI (risk ratio [RR], 2.18; 95% confidence interval [CI], 1.28–3.70) and cardiac death (RR, 1.39; 95% CI, 1.04– 1.86) during follow-up, as well with a tendency toward an increase in all-cause mortality (RR, 1.21; 95% CI, 0.98–1.50). Periprocedural PPI post-TAVR was not associated with any increased risk of all-cause mortality at 1 year (RR, 1.03; 95% CI, 0.9–1.18), yet a tendency toward a protective effect on cardiac death was observed (RR, 0.78; 95% CI, 0.60–1.03). Conclusions—New-onset LBBB post-TAVR is a marker of an increased risk of cardiac death and need for PPI at 1-year follow-up. The need for PPI early post-TAVR did not increase the risk of death. (Circ Cardiovasc Interv. 2016;9:e003635. DOI: 10.1161/CIRCINTERVENTIONS.115.003635.)