New-Onset Left Bundle Branch Block After TAVR and Adverse Clinical Outcomes

Background New-onset left bundle branch block (LBBB) is the most frequently observed conduction disturbance following transcatheter aortic valve replacement (TAVR). However, its long-term clinical and functional implications remain incompletely characterized. We performed a contemporary systematic review and meta-analysis to evaluate the association of post-TAVR LBBB with mortality, heart failure (HF) hospitalization, ventricular function, and permanent pacemaker implantation (PPI). Methods A systematic search of PubMed/MEDLINE, Embase, Cochrane Library, and Google Scholar was performed from inception through June 2026 according to PRISMA guidelines. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Newcastle-Ottawa Scale. Randomized, registry-based, and observational studies comparing outcomes after TAVR in patients with and without new-onset LBBB were included. The primary outcome was 1-year all-cause mortality. Secondary outcomes included cardiovascular mortality, HF hospitalization or readmission, PPI, and change in left ventricular ejection fraction (LVEF) from baseline to 1 year following TAVR. Random-effects models were used to calculate pooled risk ratios (RR) and mean differences with 95% confidence intervals. Heterogeneity was assessed using the I 2 statistic. Results Eighteen studies comprising 162,622 patients were included: 28,857 with new-onset LBBB and 133,765 without LBBB. New-onset LBBB was associated with higher 1-year all-cause mortality (RR 1.31, 95% CI 1.16-1.48; P<0.00001; I 2 =42%) and cardiovascular mortality (RR 1.48, 95% CI 1.23-1.78; P<0.0001; I 2 =26%). Patients with LBBB had a higher risk of HF hospitalization or readmission (RR 1.22, 95% CI 1.19-1.24; P<0.00001; I 2 =0%). The strongest observed association was with PPI, with a more than twofold increase in risk among patients who developed LBBB (RR 2.28, 95% CI 1.67-3.11; P<0.00001). Although baseline LVEF was comparable between groups (MD –1.62%, 95% CI –3.76 to 0.52; P=0.14), patients with LBBB demonstrated a greater decline in LVEF at 1 year (MD –3.12%, 95% CI –4.37 to –1.88; P<0.00001; I 2 =40%), consistent with adverse ventricular remodeling and impaired functional recovery following TAVR. Conclusions New-onset LBBB after TAVR is associated with a distinct high-risk clinical profile characterized by increased mortality, greater HF burden, progressive ventricular dysfunction, and substantially higher rates of pacemaker implantation. These findings suggest that conduction system injury following TAVR may carry clinical consequences that extend beyond the periprocedural period. These findings emphasize the need to develop techniques and TAVR designs that minimize conduction system injury.