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.