INTRODUCTION
Transcatheter aortic valve replacement (TAVR) is an increasingly popular alternative to surgical valve replacement and is indicated for a broad range of patients with aortic stenosis. In an analysis of the Thoracic Surgeons–American College of Cardiology Transcatheter Valve Therapy (TVT) Registry, there were more than 100,000 TAVR performed between 2015 to 2017 with an positive trend(1). Despite improvement in TAVR technology and device iterations, the need for subsequent pacemaker implantation post TAVR remains a common complication (2). The close relationship of the conduction system to the aortic annulus and subsequent injury with the prosthetic stent frame may result in high-grade or complete cessation of atria-ventricular (AV) conduction. Factors predicting downstream pacemaker implantation include both modifiable factors (type of valve, depth of implantation) as well as non-modifiable factors (increased age, presence of right bundle branch block, length of membranous septum) (3, 4). Furthermore, pacemaker implantation is associated with increased periprocedural morbidity and mortality(2).
Though multiple studies have elucidated risk factors of periprocedural high grade AV block, the incidence and predictors of delayed AV conduction block remains poorly understood. New onset high grade conduction system disease has been noted in small studies opting for routine post-TAVR rhythm monitoring(5, 6). Delayed high grade AV block has been inconsistently defined as occurring sometime after valve implantation, although late bradyarrhythmias are not uncommon and remain clinically significant(7, 8). It remains unclear if delayed AV block is sporadic or occurs in a time-dependent manner after TAVR. Hence post-TAVR monitoring studies have chosen empirically defined time intervals to assess incidence of delayed AV block. (9-11) In this study, we used a nationwide registry to study the incidence and timing of post-discharge pacemaker impanation after index admission for TAVR.