Introduction:
The subcutaneous implantable cardioverter defibrillator (S-ICD) is an
alternative to a transvenous ICD (TV-ICD) in patients who necessitate
prevention from sudden cardiac death without a concurrent need for
cardiac pacing.1, 2 Current factors considered by
clinicians when determining the appropriate type of ICD to implant
include ECG characteristics, body habitus, comorbidities, and patient
preference.3-6 In addition, the 2017 American Heart
Association/American College of Cardiology/Heart Rhythm Society
(AHA/ACC/HRS) guidelines give a class I recommendation to S-ICDs over
TV-ICDs in patients with high infectious risk, tricuspid regurgitation,
and challenging venous access.7-12 One of the most
common indications for extraction or removal of any ICD is device
infection. However, other S-ICD patients are later determined to need
bradycardia pacing, cardiac resynchronization pacing, or antitachycardia
pacing (ATP) for recurrent monomorphic ventricular tachycardia and
require device removal and transvenous device implantation. To date,
there are limited data on the how often a patient who undergoes
implantation of the S-ICD eventually needs to have the system removed
and for which reasons. Only two real-world studies have been published
on rates of S-ICD extraction with discordant extraction rates from
2.85% to 12.9%.13-14 Better characterizing rates of
system extraction may provide insight into the overall risk of the S-ICD
in specific patient populations, and indications for S-ICD extraction
may further inform device selection. Accordingly, the goal of the
present study is to assess incidence of and indications for S-ICD
extraction in a large, multihospital healthcare system.