Impact of Baseline Atrial Fibrillation on Conduction Disturbances After TAVR: Insights from a Large Cohort Study.

Background: Pre-existing atrial fibrillation (AF) is common among patients undergoing transcatheter aortic valve replacement (TAVR). However, evidence regarding its impact on the risk of permanent pacemaker (PPM) implantation and other conduction disturbances (CDs) after TAVR remains inconsistent. The aim of this study was to assess the effect of baseline heart rhythm on the risk of conduction abnormalities following TAVR. Methods: This study included patients with severe AS who underwent TAVR using either balloon-expandable (BEVs) or self-expanding valves (SEVs). The primary endpoint was the incidence of PPM implantation and new or worsening left bundle branch block (LBBB) after TAVR according to baseline rhythm (sinus rhythm vs. AF). Secondary endpoints were predictors of PPM implantation, LBBB, the occurrence of periprocedural stroke, and in-hospital mortality. Results: A total of 5195 TAVR patients were included: 3560 with baseline sinus rhythm and 1635 with baseline AF. PPM implantation was more frequent in patients with AF than in those with sinus rhythm (17% vs. 15%, p = 0.033), whereas new or worsening LBBB was less common (11% vs. 14%, p = 0.026). After adjustment with multivariable logistic regression, these associations were no longer statistically significant (PPM implantation: OR 1.156, 95% CI 0.969-1.379, p = 0.108; new or worsening LBBB: OR 0.826, 95% CI 0.676-1.010, p = 0.062). Independent peri-procedural predictors of PPM implantation included baseline first-degree AV block, pre-procedural RBBB, the use of self-expandable valves, implantation of larger valve sizes (≥23 mm), and the need for valve repositioning. Conclusions: In this large cohort, baseline AF was not associated with an increased risk of PPM implantation or new onset LBBB compared with sinus rhythm. These findings suggest that baseline rhythm alone should not be considered an independent predictor of PPM implantation or CDs following TAVR.