Trends and In-Hospital Outcomes Associated With Adoption of the Subcutaneous Implantable Cardioverter Defibrillator in the United States.
Trends and in-hospital outcomes associated with early adoption of the subcutaneous implantable cardioverter defibrillator (S-ICD) in the United States have not been described.



To describe early use of the S-ICD in the United States and to compare in-hospital outcomes among patients undergoing S-ICD vs transvenous (TV)-ICD implantation.



A retrospective analysis of 393 734 ICD implants reported to the National Cardiovascular Data Registry ICD Registry, a nationally representative US ICD registry, between September 28, 2012 (US Food and Drug Administration S-ICD approval date), and March 31, 2015, was conducted. A 1:1:1 propensity-matched analysis of 5760 patients was performed to compare in-hospital outcomes among patients with S-ICD with those of patients with single-chamber (SC)-ICD and dual-chamber (DC)-ICD.



Analysis of trends in S-ICD adoption as a function of total ICD implants and comparison of in-hospital outcomes (death, complications, and defibrillation threshold [DFT] testing) among S-ICD and TV-ICD recipients.



Of the 393 734 ICD implants evaluated during the study period, 3717 were S-ICDs (0.9%). A total of 109 445 (27.8%) of the patients were female; the mean (SD) age was 67.03 (13.10) years. Use of ICDs increased from 0.2% during the fourth quarter of 2012 to 1.9% during the first quarter of 2015. Compared with SC-ICD and DC-ICD recipients, those with S-ICDs were more often younger, female, black, undergoing dialysis, and had experienced prior cardiac arrest. Among 2791 patients with S-ICD who underwent DFT testing, 2588 (92.7%), 2629 (94.2%), 2635 (94.4%), and 2784 (99.7%) were successfully defibrillated (≤65, ≤70, ≤75, and ≤80 J, respectively). In the propensity-matched analysis of 5760 patients, in-hospital complication rates associated with S-ICDs (0.9%) were comparable to those of SC-ICDs (0.6%) (P = .27) and DC-ICD rates (1.5%) (P = .11). Mean (SD) length of stay after S-ICD implantation was comparable to that after SC-ICD implantation (1.1 [1.5] vs 1.0 [1.2] days; P = .77) and less than after DC-ICD implantation (1.1 [1.5] vs 1.2 [1.5] days; P < .001).



The use of S-ICDs is rapidly increasing in the United States. Early adoption has been associated with low complication rates and high rates of successful DFT testing despite frequent use in patients with a high number of comorbidities.
Division of Cardiology, Duke University Hospital, Durham, North Carolina2Duke Clinical Research Institute, Durham, North Carolina.
Daniel J
DJ
Friedman
Yale University School of Medicine, New Haven, Connecticut.
Craig S
CS
Parzynski
Veterans Affairs Eastern Colorado Health Care System, Denver5Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora.
Paul D
PD
Varosy
Division of Cardiology, University of Washington, Seattle.
Jordan M
JM
Prutkin
Division of Cardiology, University of Washington, Seattle.
Kristen K
KK
Patton
Cooper Medical School of Rowan University, Camden, New Jersey.
Ali
A
Mithani
Cooper Medical School of Rowan University, Camden, New Jersey.
Andrea M
AM
Russo
Yale University School of Medicine, New Haven, Connecticut.
Jeptha P
JP
Curtis
Division of Cardiology, Duke University Hospital, Durham, North Carolina2Duke Clinical Research Institute, Durham, North Carolina.
Sana M
SM
Al-Khatib
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000628:therapy*; D015897:Comorbidity; D017147:Defibrillators, Implantable; D005260:Female; D006323:Heart Arrest; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D012042:Registries; D006435:Renal Dialysis; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States