Limitations:
Multiple noteworthy limitations exist in our study. Due to inherent
administrative nature of this database, coding errors could result in
identification of comorbidities as well as procedures. The database
lacks the procedural characteristics of the TAVR (type and size of
valve) as well as the lack of post-procedural complications. The extent
of baseline electrocardiographic findings (QRS duration, PR interval) is
limited. Post-discharge follow-up and use of ambulatory monitoring
remains unknown, which could influence the timing of pacemaker
implantation. It is possible that some patients may have died
unexpectedly during the initial months post TAVR before they could reach
the hospital. This could underestimate the true incidence of conduction
system abnormalities. We purposefully excluded defibrillator
implantation as well as CRT implantation in both index as well as
follow-up patients in order to avoid any confusion regarding indication
for implantation in late follow-up. However, given these limitations,
the large sample size of the NRD database makes it optimal for capturing
the small but significant increase in pacemaker implantations after
discharge.