Elsevier

Heart Rhythm

Volume 19, Issue 7, July 2022, Pages 1109-1115
Heart Rhythm

Clinical
Devices
Age-related differences and associated mid-term outcomes of subcutaneous implantable cardioverter-defibrillators: A propensity-matched analysis from a multicenter European registry

https://doi.org/10.1016/j.hrthm.2022.02.029Get rights and content

Background

A few limited case series have shown that the subcutaneous implantable cardioverter-defibrillator (S-ICD) system is safe for teenagers and young adults, but a large-scale analysis currently is lacking.

Objectives

The purpose of this study was to compare mid-term device-associated outcomes in a large real-world cohort of S-ICD patients, stratified by age at implantation.

Methods

Two propensity-matched cohorts of teenagers + young adults (≤30 years old) and adults (>30 years old) were retrieved from the ELISIR Registry. The primary outcome was the comparison of inappropriate shock rate. Complications, freedom from sustained ventricular arrhythmias, and overall and cardiovascular mortality were deemed secondary outcomes.

Results

Teenagers + young adults represented 11.0% of the entire cohort. Two propensity-matched groups of 161 patients each were used for the analysis. Median follow-up was 23.1 (13.2–40.5) months. In total, 15.2% patients experienced inappropriate shocks, and 9.3% device-related complications were observed, with no age-related differences in inappropriate shocks (16.1% vs 14.3%; P = .642) and complication rates (9.9% vs 8.7%; P = .701). At univariate analysis, young age was not associated with increased rates of inappropriate shocks (hazard ratio [HR] 1.204 [0.675–2.148]: P = .529). At multivariate analysis, use of the SMART Pass algorithm was associated with a strong reduction in inappropriate shocks (adjusted HR 0.292 [0.161–0.525]; P <.001), whereas arrhythmogenic right ventricular cardiomyopathy (ARVC) was associated with higher rates of inappropriate shocks (adjusted HR 2.380 [1.205–4.697]; P = .012).

Conclusion

In a large multicenter registry of propensity-matched patients, use of the S-ICD in teenagers/young adults was safe and effective. The rates of inappropriate shocks and complications between cohorts were not significantly different. The only predictor of increased inappropriate shocks was a diagnosis of ARVC.

Introduction

In the last decade, the subcutaneous implantable cardioverter-defibrillator (S-ICD) has become a cornerstone in sudden cardiac death (SCD) prevention as an established alternative to the transvenous (TV) ICD among patients not needing pacing or cardiac resynchronization therapy.1 SCD prevention with ICD therapy has also been demonstrated to be safe and effective in young patients with ventricular arrhythmias, arrhythmogenic cardiomyopathies, and congenital heart diseases.2 Young patients often represent the most suitable candidates for an entirely S-ICD system because they have to face a lifetime of device therapy and they rarely have a pre-existing or concurrent pacing or cardiac resynchronization therapy indication. Indeed, TV-ICD bears the risk of significant lead-related complications as well as potential venous access issues, which pose significant concerns regarding their mid-term use in young patients. However, the S-ICD offers lower rates and safer management of lead- and major procedure–related complications, as well as easier management of these events, especially with regard to lead extraction.3, 4, 5

To date, a few limited case series and experiences with S-ICD in teenagers and young adults have shown that the S-ICD system is safe and feasible in this population, with a rate of inappropriate shocks (IAS) comparable to that of TV-ICD6, 7; however, a focused analysis on a large scale currently is lacking in this setting. Therefore, the aim of this study was to evaluate the mid-term outcomes in the largest independent European S-ICD registry based on baseline patient profiles and ages at implantation.

Section snippets

Registry population

The ELISIR project (Experience from the Long-term Italian S-RCD registry) is a European, multicenter, open-label, independent, physician-initiated observational registry, whose characteristics and preliminary composition have been previously described.8, 9 At the time of this manuscript drafting, a total of 21 public and private health care institutions from 4 different countries in Europe were involved in the registry. All consecutive patients meeting current guideline indications for ICD

Patient population

Teenagers and young adults represented 11.0% of the patients (51 teenagers; 113 young adults) in the registry. After extraction and propensity matching, 2 cohorts of 161 patients each were retrieved and used for the study. Considering not-matched variables, teenagers and young adults at the time of S-ICD implantations were more active (body mass index 23.3 ± 4.2 vs 26.0 ± 4.2; P <.001; sport practice rate 21.3% vs 12.4%; P = .026) and had lower rates of cardiovascular risk factors compared to

Discussion

The aim of this study was to summarize the mid-term outcomes among the recipients of an S-ICD in a large, multicenter, European registry based on age-related differences in patient baseline clinical profiles. The main points of this study are as follows. First, in a large, multicenter, real-world registry encompassing a broad population, teenagers (<20 years old) and young adults (20–30 years old) represented 11.0% of S-ICD recipients. Teenagers and young adults received an S-ICD more

Conclusion

In a large multicenter European registry of patients with S-ICD, 11.0% of all recipients were teenagers or young adults. Use of an S-ICD in teenagers/young adults was safe and effective, and the rates of complications and IAS between teenagers/young adults and adults were not significantly different. The only predictor of increased IAS was a diagnosis of ARVC.

References (19)

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Cited by (18)

  • The subcutaneous implantable cardioverter-defibrillator should be reserved for niche indications

    2022, Heart Rhythm O2
    Citation Excerpt :

    Although failing to reach statistical significance, the trend of higher IAS with the S-ICD is supported by a multitude of real-world registries. An Italian S-ICD registry reported an IAS rate of 9.4% in 2 years, similar to rates reported worldwide in the EFFORTLESS (Evaluation of Factors Impacting Clinical Outcome and Cost Effectiveness Of the S-ICD) trial (11.7% in 3 years).17,18 Given that IAS are psychologically harmful and lead to increased health care utilization, the S-ICD cannot be considered as a first option until any issues are addressed.19

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Funding Sources: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Disclosures: Dr Santini is a consultant/speaker for Boston Scientific. Dr Tondo is a member of Boston Scientific advisory board. Dr Steffel has received consultant and/or speaker fees Boston Scientific; and has received grant support through his institution from Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

1

Dr Simone Gulletta and Dr Alessio Gasperetti shared first co-authorship.

2

Dr Giovanni B. Forleo and Dr Roland Tilz shared last co-authorship. ClinicalTrials.gov Identifier: NCT0473876

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