Membranous septum length predicts conduction disturbances following transcatheter aortic valve replacement

Insufficient distance between membranous septum (MS) length and implant depth (ID) may aggravate mechanical compression of the conduction tissue by transcatheter aortic valve replacement (TAVR) prosthesis. We investigated the implication of MS length measured in the coronal view (coronal MS length) compared with infra-annular MS length from stretched vessel image to predict conduction disturbances following TAVR with CoreValve/Evolut R valves (Medtronic, Minneapolis, Minn). Among 195 consecutive patients undergoing TAVR with CoreValve/Evolut R valves, we evaluated coronal, infra-annular MS lengths and ID, as well as MS length minus ID (ΔMSID) using pre-TAVR computed tomography and postprocedural angiography. Within 30 days, 6 (3.1%) required permanent pacemaker implantation and 31 (16.4%) developed left bundle branch block. When taking into account pre- and postprocedural parameters, multivariable logistic regression analysis revealed either coronal ΔMSID (odds ratio, 0.80; 95% confidence interval, 0.72-0.89; P