The entirely subcutaneous implantable cardioverter-defibrillator: initial clinical experience in a large Dutch cohort.
OBJECTIVE
The purpose of the study was to evaluate the efficacy and safety of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD).


BACKGROUND
A new entirely S-ICD has been introduced, that does not require lead placement in or on the heart. The authors report the largest multicenter experience to date with the S-ICD with a minimum of 1-year follow-up in the first 118 Dutch patients who were implanted with this device.


METHODS
Patients were selected if they had a class I or IIa indication for primary or secondary prevention of sudden cardiac death. All consecutive patients from 4 high-volume centers in the Netherlands with an S-ICD implanted between December 2008 and April 2011 were included.


RESULTS
A total of 118 patients (75% males, mean age 50 years) received the S-ICD. After 18 months of follow-up, 8 patients experienced 45 successful appropriate shocks (98% first shock conversion efficacy). No sudden deaths occurred. Fifteen patients (13%) received inappropriate shocks, mainly due to T-wave oversensing, which was mostly solved by a software upgrade and changing the sensing vector of the S-ICD. Sixteen patients (14%) experienced complications. Adverse events were more frequent in the first 15 implantations per center compared with subsequent implantations (inappropriate shocks 19% vs. 6.7%, p = 0.03; complications 17% vs. 10%, p = 0.10).


CONCLUSIONS
This study demonstrates that the S-ICD is effective in terminating ventricular arrhythmias. There is, however, a considerable percentage of ICD related adverse events, which decreases as the therapy evolves and experience increases.
Department of Cardiology, Academic Medical Center, Amsterdam, the Netherlands.
Louise R A
LR
Olde Nordkamp
Lara
L
Dabiri Abkenari
Lucas V A
LV
Boersma
Alexander H
AH
Maass
Joris R
JR
de Groot
Antonie J H H M
AJ
van Oostrom
Dominic A M J
DA
Theuns
Luc J L M
LJ
Jordaens
Arthur A M
AA
Wilde
Reinoud E
RE
Knops
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy*; D002648:Child; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies; D040521:Subcutaneous Tissue / Q000502:physiology; D016896:Treatment Outcome; D055815:Young Adult