Long-Term Clinical Outcomes of Subcutaneous Versus Transvenous Implantable Defibrillator Therapy.
Transvenous implantable cardioverter-defibrillators (TV-ICDs) improve survival in patients at risk for sudden cardiac death, but complications remain an important drawback. The subcutaneous ICD (S-ICD) was developed to overcome lead-related complications. Comparison of clinical outcomes of both device types in previous studies was hampered by dissimilar patient characteristics.



This retrospective study compares long-term clinical outcomes of S-ICD and TV-ICD therapy in a propensity-matched cohort.



The authors analyzed 1,160 patients who underwent S-ICD or TV-ICD implantation in 2 high-volume hospitals in the Netherlands. Propensity matching for 16 baseline characteristics, including diagnosis, yielded 140 matched pairs. Clinical outcomes were device-related complications requiring surgical intervention, appropriate and inappropriate ICD therapy, and were reported as 5-year Kaplan-Meier rate estimates.



All 16 baseline characteristics were balanced in the matched cohort of 140 patients with S-ICDs and 140 patients with TV-ICDs (median age 41 years [interquartile range: 30 to 52 years] and 40% women). The complication rate was 13.7% in the S-ICD group versus 18.0% in the TV-ICD group (p = 0.80). The infection rate was 4.1% versus 3.6% in the TV-ICD groups (p = 0.36). Lead complications were lower in the S-ICD arm compared with the TV-ICD arm, 0.8% versus 11.5%, respectively (p = 0.03). S-ICD patients had more nonlead-related complications than TV-ICD patients, 9.9% versus 2.2%, respectively (p = 0.047). Appropriate ICD intervention (antitachycardia pacing and shocks) occurred more often in the TV-ICD group (hazard ratio [HR]: 2.42; p = 0.01). The incidence of appropriate (TV-ICD HR: 1.46; p = 0.36) and inappropriate shocks (TV-ICD HR: 0.85; p = 0.64) was similar.



The complication rate in patients implanted with an S-ICD or TV-ICD was similar, but their nature differed. The S-ICD reduced lead-related complications significantly, at the cost of nonlead-related complications. Rates of appropriate and inappropriate shocks were similar between the 2 groups.
Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Medical Center, University of Amsterdam, Amsterdam, the Netherlands. Electronic address: t.f.brouwer@amc.uva.nl.
Tom F
TF
Brouwer
Department of Cardiology, Leiden University Medical Center, University of Leiden, Leiden, the Netherlands.
Dilek
D
Yilmaz
Department of Clinical Epidemiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Robert
R
Lindeboom
Department of Cardiology, Leiden University Medical Center, University of Leiden, Leiden, the Netherlands.
Maurits S
MS
Buiten
Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Louise R A
LR
Olde Nordkamp
Department of Cardiology, Leiden University Medical Center, University of Leiden, Leiden, the Netherlands.
Martin J
MJ
Schalij
Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Arthur A
AA
Wilde
Department of Cardiology, Leiden University Medical Center, University of Leiden, Leiden, the Netherlands.
Lieselot
L
van Erven
Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Reinoud E
RE
Knops
D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome
complications; implantable cardioverter-defibrillator; shocks; subcutaneous implantable cardioverter-defibrillator; survival; transvenous implantable cardioverter-defibrillator