Long-Term Clinical Outcomes of Subcutaneous Versus Transvenous Implantable

Fro Am Le Am res on Ju Dr Ma BACKGROUND 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. OBJECTIVES This retrospective study compares long-term clinical outcomes of S-ICD and TV-ICD therapy in a propensity-matched cohort. METHODS 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. RESULTS 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 1⁄4 0.80). The infection rate was 4.1% versus 3.6% in the TV-ICD groups (p 1⁄4 0.36). Lead complications were lower in the S-ICD arm compared with the TV-ICD arm, 0.8% versus 11.5%, respectively (p 1⁄4 0.03). S-ICD patients had more nonlead-related complications than TV-ICD patients, 9.9% versus 2.2%, respectively (p 1⁄4 0.047). Appropriate ICD intervention (antitachycardia pacing and shocks) occurred more often in the TV-ICD group (hazard ratio [HR]: 2.42; p 1⁄4 0.01). The incidence of appropriate (TV-ICD HR: 1.46; p 1⁄4 0.36) and inappropriate shocks (TV-ICD HR: 0.85; p 1⁄4 0.64) was similar. CONCLUSIONS 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. (J Am Coll Cardiol 2016;68:2047–55) © 2016 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). I mplantable cardioverter-defibrillators (ICDs) improve survival of patients at increased risk of sudden cardiac death (SCD) (1,2). Advances in ICD programming have reduced the burden of shocks, m the Heart Center, Department of Clinical and Experimental Card sterdam, Amsterdam, the Netherlands; Department of Cardiology, Leid iden, the Netherlands; and the Department of Clinical Epidemiology, A sterdam, the Netherlands. The Department of Cardiology of Leiden U earch and fellowship grants from Biotronik, Boston Scientific, GE Healthca the scientific board of Sorin. Dr. Knops received personal fees and resear de Medical. All other authors have reported that they have no relationshi s. Brouwer and Yilmaz contributed equally to this work. nuscript received February 25, 2016; revised manuscript received July 28 but device-related complications remain an important drawback of transvenous implantable cardioverterdefibrillator (TV-ICD) therapy, resulting in significant morbidity (3). Transvenous sensing and defibrillation iology, Amsterdam Medical Center, University of en University Medical Center, University of Leiden, cademic Medical Center, University of Amsterdam, niversity Medical Center has received unrestricted re, Medtronic, and St. Jude Medical. Dr. Wilde serves ch grants from Boston Scientific, Medtronic, and St. ps relevant to the contents of this paper to disclose. , 2016, accepted August 9, 2016. ABBR EV I A T I ON S