Association between Atrial Fibrillation and the risk of New-Onset Left bundle branch block following Transcatheter Mitral Valve Replacement: a retrospective analysis of the National Inpatient Sample

Background Transcatheter mitral valve replacement (TMVR) offers an alternative for high-risk patients with mitral valve disease. Atrial fibrillation (AF) frequently coexists with mitral valve disease, while new-onset left bundle branch block (NLBBB) following transcatheter valve interventions may adversely affect cardiac function and necessitate permanent pacemaker implantation. However, the association between pre-existing AF and NLBBB following TMVR remains inadequately characterized. Methods This retrospective study analyzed TMVR hospitalizations with or without AF using National Inpatient Sample data from 2016 to 2022. The primary outcome was the risk of NLBBB following TMVR. The association between AF and NLBBB risk was evaluated using multivariable logistic regression, adjusting for sociodemographic characteristics and comorbidities. Sensitivity analyses were performed using inverse probability of treatment weighting (IPTW) and interaction test to validate the robustness of our findings. Results Among 1,754 patients undergoing TMVR, 65.6% (n = 1,150) had documented AF. AF patients were significantly older (74.63 ± 9.91 vs. 68.24 ± 13.88 years; P < 0.001) and exhibited higher prevalence of peripheral vascular disease (P = 0.004) and hypothyroidism (P = 0.024). The incidence of NLBBB was 4.61% in the AF cohort. Multivariable analysis demonstrated that AF was independently associated with increased NLBBB risk (aOR 2.09; 95% CI 1.13–3.84; P = 0.018), the finding that remained consistent after IPTW analysis (ATT 1.90; 95% CI 1.07–3.69; P = 0.030). Further stratification revealed that persistent AF significantly correlated with NLBBB development (ATT 2.74; 95% CI 1.23–6.09; P = 0.014), whereas paroxysmal AF did not show statistical significance (ATT 1.84; 95% CI 0.88–3.82; P = 0.100). Conclusions Patients with AF, particularly persistent AF, demonstrated significantly higher risk of NLBBB following TMVR.