Left bundle branch block and risk for pacemaker implantation after TAVI: insights from the SwissTAVI Cohort Study

Background Approximately 10–20% of patients undergoing transcatheter aortic valve implantation (TAVI) require permanent pacemaker implantation (PPI). As the conduction system is located close to the aortic root, mechanical interaction during valve implantation is the main cause of new conduction disturbances. While pre-procedural right bundle branch block is an established risk factor for PPI after TAVI, the association with left bundle branch block (LBBB) is less understood. Identifying patients at high risk of PPI may help to better anticipate these post-procedural complications and prevent readmissions. The aim of this study was to evaluate whether pre-existing or new-onset LBBB (occurring after TAVI) is associated with higher odds of PPI within 30 days after TAVI. Methods This study included participants from the SwissTAVI cohort study (NCT01368250) who underwent TAVI between January 2017 and December 2024, and had an available baseline electrocardiogram (ECG) showing either no intraventricular conduction delay or LBBB. Participants with prior pacemaker implantation or valve-in-valve procedures were excluded. The association between LBBB status (no LBBB, pre-procedural LBBB, and new-onset LBBB after TAVI) and PPI within 30 days was assessed using logistic regression, adjusting for age, comorbidities (diabetes mellitus, arterial hypertension, renal function), baseline ECG rhythm, baseline atrioventricular block, and prosthetic valve size. Secondary analyses assessed sex-specific associations and 30-day mortality. Results A total of 10,319 patients (48% women) undergoing TAVI were included in the study. A new PPI was required in 1,322 (12.8%). Among the participants, 71.8% (n=7,404) had no LBBB, 11.3% (n=1,166) had pre-procedural LBBB, and 16.9% (n=1,749) developed new-onset LBBB. After adjustment, both pre-procedural LBBB (OR 1.28, 95% CI 1.07–1.53) and new-onset LBBB (OR 1.51, 95% CI 1.29–1.75) were associated with higher odds of 30-day PPI. These associations were largely consistent in both women and men. Pre-procedural (adjusted OR 0.98, 95% CI 0.62–1.48) or new-onset LBBB (adjusted OR 0.86, 95% CI 0.57–1.26) were not significantly associated with higher 30-day mortality. Conclusions Both pre-procedural and new-onset LBBB were significantly associated with increased odds of PPI within 30 days after TAVI. The highest odds were observed in patients with new-onset LBBB. These findings suggest that LBBB, and not only RBBB, should be included in pre-procedural risk stratification.