The International SubcutaneouS Implantable Cardioverter Defibrillator Registry (iSuSI)

Study Overview
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Brief Summary
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The entirely subcutaneous implantable defibrillator (S-ICD) (Emblem, Boston Scientific, Marlborough, MA, USA) was introduced as a new therapeutic alternative to the conventional transvenous ICD in 2009 and implantations are rapidly expanding since then.1 Implantation of the S-ICD seems to reduce implant-related perioperative complications such as pneumothorax, hematoma and cardiac tamponade. The aim of this multicenter registry is thus to assess the outcome of patients following an S-ICD implantation in a real-world setting.

Detailed Description
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The S-ICD has a CE mark and is FDA approved since 2012 and is mentioned as a potential therapy strategy in the current AHA guidelines on the management of patients with ventricular arrhythmias.2 However, although implant-related complications seem to be reduced by the S-ICD in randomized controlled trials, the rate of inappropriate shocks remains high in S-ICD patients (10-13%).3-5 The most common reason for inappropriate shocks is cardiac oversensing, mostly due to T-wave oversensing or low amplitude of the subcutaneous signal, which not commonly found in patients with transvenous ICDs. Data on the role of the Defibrillation Threshold Testing (DFT), the rate of infectious complications (lead or device complications), the use of the S-ICD in children and adolescents, and the outcome of patients with an S-ICD according to their underlying cardiac substrate are sparse. The aim of this multicenter registry is thus to assess the outcome of patients following an S-ICD implantation in a real-world setting with a special focus on perioperative complication rate, the role of DFT testing in S-ICD, the use of the S-ICD in cohorts that are underrepresented in clinical studies (adolescents and geriatrics), the outcome and risk factors of ineffective, inappropriate and appropriate shocks and the differences in outcomes according to the underlying cardiac disease.

Official Title
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The International Subcutaneous Implantable Cardioverter Defibrillator Registry (iSuSi)

Conditions
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Sudden Cardiac Death

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Implantation of an S-ICD, regardless of the technique At least 1 month of follow up At least 1 post-implantation assessment, in accordance to the routine clinical practice of every center (e.g. in person visit or remote follow up) Exclusion Criteria: - none

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall complication rate | combination of device related complications and inappropriate shocks | through study completion, an average of 2 years | 
| Rate of appropriate shocks | Appropriate therapies delivered by the devices | through study completion, an average of 2 years | 
| Rate of inappropriate shocks | Inappropriate therapies delivered by the devices | through study completion, an average of 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Device-related complication rate | Rate of complications pertaining to the device | immediately after the intervention/procedure/surgery | 
| DFT impact | Impact of defibrillator function test (DFT) on long term arrhythmia outcome or mortality | 2 year | 
| Rate of replacements | Generator replacements | 2 year | 
| Role of Gender in primary outcomes | Analysis of the potential role of gender on the primary outcomes | through study completion, an average of 2 year | 
| Rate of device upgrades | need for device upgrade due to pacing needs | through study completion, an average of 2 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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subcutaneous implantable cardioverter defibrillator