Prognostic implications of left bundle branch block following transcatheter aortic valve replacement: a systematic review and meta-analysis
R Motta, D Hora, K Chagas, L Barbosa, L Silva, W Furtado, G Carvalho, A Rosa FilhoAbstract
Background
Transcatheter Aortic Valve Replacement (TAVR) is the established treatment for severe aortic stenosis. A frequent procedural complication is the new onset of Left Bundle Branch Block (LBBB), with incidence rates varying widely (up to 65%) depending on the valve type and follow-up definition. LBBB can lead to ventricular dyssynchrony, which may compromise left ventricular function and potentially result in adverse long-term outcomes, though the prognostic significance remains controversial across different studies.
Purpose
We aimed to conduct a systematic review and meta-analysis to assess the prognostic impact of new-onset persistent LBBB following TAVR on all-cause mortality, cardiovascular mortality, and permanent pacemaker implantation (PPI).
Methods
We systematically searched PubMed, Embase, and Cochrane databases for studies comparing outcomes in TAVR patients with LBBB. The primary outcomes analyzed were all-cause mortality, cardiovascular mortality, and permanent pacemaker implantation (PPI) and heart failure hospitalization. Statistical analyses were performed using a random effects model. Statistical analyses were performed using R software version 5.4.1. We assessed the effect on binary endpoints by comparing the proportion of events. We compared the results using Odds ratio (OR) under a random effects model with 95% Confidence Intervals (CI), with a p-value < 0.05 considered for statistical significance.
Results
A total of 32 studies were included, comprising 4432 patients. The pooled event rates for the three different outcomes showed varying magnitudes and degrees of consistency. All-cause mortality was 16.62 events per 100 observations (95% CI: 10.65 - 25.00, p < 0.0001; I²=92.7%). Cardiovascular death was 12.34 events per 100 observations (95% CI: 10.21 - 14.85, p = 0.1164; I²=41.2%). Permanent Pacemaker Implantation (PPI) demonstrated 12.40 events per 100 observations (95% CI: 8.92 - 16.99, p = 0.0020; I²=69.1%). Heart Failure Rehospitalization showed the highest overall pooled rate at 31.52 events per 100 observations (95% CI: 11.82 - 61.24 p < 0.0001; I²=88.2%).
Conclusion
Our meta-analysis confirms that adverse event rates remain substantial, particularly for all-cause mortality and heart failure rehospitalization. Crucially, the high heterogeneity observed across most outcomes suggests significant variability in reporting or patient factors across studies. Future research must identify the root causes of this substantial heterogeneity to improve risk stratification and clinical practice.