Membranous septum length as predictor for permanent pacemaker implantation after TAVI

Abstract

Abstract Background High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Extension of indication for TAVI towards subjects with lower surgical risk requires to reduce the likelihood for the requirement of permanent pacemaker (PPM) implantation. Data on the role of membranous septum length as potential predictor for AV block after TAVI are scarce. Purpose We examined the role of membranous septum length as potential predictor for AV block and the need for PPM implantation in a large cohort of consecutive subjects after TAVI. Methods In a cohort of 1365 patients without prior permanent pacemaker who underwent transfemoral TAVI, clinical and procedural characteristics were assessed systematically. Based on cardiac computed tomography performed prior to TAVI, membranous septum length was measured orthogonal to the anulus plane (see figure). Results Median age of subjects was 81 (IQR 7) years, 50% were male. Logistic euroSCORE was 12.8 (IQR 15.7), STS score 3 (2.7). 9,8% of subjects had a pre-interventional complete right bundle branch block (RBBB). 71% of patients received a balloon-expandable, 29% a self-expandable valve. In n=153 patients (11.2%), PPM implantation was necessary due to high-degree AV block. Median membranous septum length was 2.9 mm (IQR 2.5mm) in subjects who received a PPM versus 4.3 mm (IQR 3.2 mm) in subjects who did not need a PPM (p=0.061). In univariate regression analysis, pre-interventional complete RBBB (p<0.001, OR 7.8), implantation of a self-expandable prosthesis (p=0002, OR 1.7) and membranous septum length (p=0.027, OR 0.9 per 1 mm) were identified as significant predictors for PPM implantation. In multivariate regression analysis, all parameters remained significant, including membranous septum length (p=0.009, OR 0.9 per 1 mm). Conclusion In a large cohort of consecutive patients, we were able to confirm the significant independent predictive value of membranous septum length, in addition to pre-interventional complete RBBB or implantation of a self-expandable prosthesis, regarding the occurrence of post-procedural AV block with the need for PPM implantation. The results may contribute to improved risk stratification for potential PPM implantation after TAVI. Funding Acknowledgement Type of funding sources: None.