Pilot Study of Hypertrophic Cardiomyopathy & Implantable Cardioverter Defibrillator Assessment: (Subcutaneous vs Transvenous)

Study Overview
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Brief Summary
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Pilot randomised trial to assess recruitment for a larger trial to compare the efficacy and adverse effects of the subcutaneous and transvenous ICD in patients with hypertrophic cardiomyopathy (HCM) and indication for ICD therapy, with no requirement for pacing

Detailed Description
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This study aims to test the feasibility of conducting a trial to investigate the use of subcutaneous implantable defibrillator (SICD) in patients with hypertrophic cardiomyopathy (HCM) and to determine whether SICD produces more complications than conventional, transvenous implantable defibrillator (TV ICD). The primary analysis for the main trial is designed to test whether the S-ICD is non-inferior to the TV-ICD with respect to the primary endpoint of inappropriate shock treatment and complications. For the incidence of the primary endpoint statistical significance and 99% confidence intervals are calculated using Cox' proportional hazards model. Non-inferiority is considered to be established if the upper boundary of the one-sided 99% confidence interval did not exceed 1.92 (absolute difference < 12%). Participant duration is expected to be 14 months. (12 months follow up post device implant) Recruitment duration expected to be 6-10 months.

Official Title
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Pilot Study of Hypertrophic Cardiomyopathy & Implantable Cardioverter Defibrillator Assessment: (Subcutaneous vs Transvenous)

Conditions
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Ventricular Arrythmia, Implantable Defibrillator User, Hypertrophic Cardiomyopathy, Implantable Cardioverter Ventricular Lead Dysfunction or Complication

Intervention / Treatment
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* Device: Implantable Cardioverter Defibrillator implant


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Hypertrophic Cardiomyopathy and a referred for ICD therapy with no pacing requirement. Exclusion Criteria: Patients with sustained ventricular tachycardia less than 170 bpm Patients having an indication for pacing therapy. E.g. sick sinus syndrome. Patients failing appropriate QRS/T-wave sensing with the automated S-ICD ECG automated patient screening provided by Boston Scientific A minimum of 1 sensing vector passing in supine, standing. Patients with incessant ventricular tachycardia Patients who have had a previous ICD implant Patient who receives cardiac contractility modulation therapy or are likely to receive cardiac contractility modulation therapy Patients with a serious known concomitant disease with a life expectancy of less than one year Patients with circumstances that prevent follow-up (no permanent home or address, transient, etc.) Patients who are unable to give informed consent Patients who are not suitable for TV-ICD implantation, according to the discretion of the physician, are not screened for enrolment (SVC occlusion).

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Pilot randomised control trial, randomised 1:1 for Transvenous: Subcutaneous
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Transvenous Implantable Defibrillator<br>Routine TV ICD implant | Device: Implantable Cardioverter Defibrillator implant<br>* ICD implant to protect patients from life threatening ventricular tachycardia or ventricular fibrillation<br>|
| Active Comparator: Subcutaneous Implantable Defibrillator<br>SICD ICD implant as per study protocol | Device: Implantable Cardioverter Defibrillator implant<br>* ICD implant to protect patients from life threatening ventricular tachycardia or ventricular fibrillation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of recruitment | Assessment of rate of recruitment per month | through study completion, expected at 10 months to 1 year | 
| Composite of inappropriate shock and ICD related complications | Rate of inappropriate shocks and ICD related complications across the patients over a 12 month period. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| All- cause mortality | % of patients who die | 12 months | 
| MACE events | Major Adverse Cardiac Event (MACE), defined as cardiac death, myocardial infarction, percutaneous coronary intervention, coronary artery bypass grafting and/or any valve surgery. | 12 months | 
| Appropriate shocks and patients with appropriate shocks | Rate over 12 months determined by IBHRE accredited Cardiac Scientist | 12 months | 
| Inappropriate shocks and patients with inappropriate shocks | Rate over 12 months determined by IBHRE accredited Cardiac Scientist | 12 months | 
| Complications | individually, defined as infections, bleedings, thrombotic events, pneumothorax, perforation/tamponade, lead reposition and lead- or device failures | 12 months | 
| Cardiac decompensation | Measured by admissions for Heart failure or unplanned outpatient appointments. | 12 months | 
| Crossovers to the other arm | Amount of patients moving from SICD to TV group and visa versa over 12 month period. | 12 months | 
| Appropriate shock treatment in ATP or monitor zone | Rate over 12 months determined by IBHRE accredited Cardiac Scientist | 12 months | 
| Quality of life assessed by SF-36 survey | Scores for the different domains are converted and pooled using a scoring key, for a total score indicating a range of low to high QOL. | 12 months | 
| Quality of life assessed by EQ5D survey | Scores for the different domains are converted and pooled using a scoring key, for a total score indicating a range of low to high QOL. | 12 months | 
| Cardiac (pre-) syncope events | rate of patients with these events over a 12 month period | 12 months | 
| Time to successful therapy | Time in months or days from implant to date of succesful therapy | 12 months | 
| First shock conversion efficacy | % of first shocks that cardiovert ventricular arrhythmia | 12 months | 
| Implant procedure time | Duration of implant from needle to skin to skin closure. | Procedure duration- average of 2 hours expected | 
| Hospitalization rate | Rate of patient hospitalisation for cardiac and non-cardiac causes over a 12 month period. | 12 months | 
| Fluoroscopy time | Amount of fluoroscopy required to complete implant procedure, expected fluoroscopy time of approximately 1 minute per patient. | Procedure duration- average of 2 hours expected | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transvenous Implantable Defibrillator, Subcutaneous Implantable Defibrillator