Implantable Defibrillator UserHICDNCT05938283
Pilot Study of Hypertrophic Cardiomyopathy & Implantable Cardioverter Defibrillator Assessment: (Subcutaneous vs Transvenous)
A study testing Implantable Cardioverter Defibrillator implant in people with Implantable Defibrillator User and Hypertrophic Cardiomyopathy, run by Barts & The London NHS Trust at 1 site in United Kingdom.
Trial summary
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 Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Implantable Defibrillator User, Hypertrophic Cardiomyopathy, Implantable Cardioverter Ventricular Lead Dysfunction or Complication
- What is being tested?
- Implantable Cardioverter Defibrillator implant
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 5 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 10 Jan 2024to 7 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Hypertrophic Cardiomyopathy and a referred for ICD therapy with no pacing requirement.
Who cannot join
- 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
Show all 11Show fewer
- 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).
Trial locations and contacts
1 site in 1 country.
About this study
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
Read the detailed description
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.
- Conditions
- Implantable Defibrillator User, Hypertrophic Cardiomyopathy, Implantable Cardioverter Ventricular Lead Dysfunction or Complication, Ventricular Arrythmia
- Being tested
- Implantable Cardioverter Defibrillator implant
- Keywords
- Transvenous Implantable Defibrillator, Subcutaneous Implantable Defibrillator
- Medical subject headings
- Cardiomyopathy, Hypertrophic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Implantable Cardioverter Defibrillator implantDevice
ICD implant to protect patients from life threatening ventricular tachycardia or ventricular fibrillation
| Study group | Role | What they receive |
|---|---|---|
| Transvenous Implantable Defibrillator | Active comparator | Routine TV ICD implant Receives: Device: Implantable Cardioverter Defibrillator implant |
| Subcutaneous Implantable Defibrillator | Active comparator | SICD ICD implant as per study protocol Receives: Device: Implantable Cardioverter Defibrillator implant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rate of recruitment
Assessment of rate of recruitment per month
Measured: 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.
Measured: 12 months
Secondary outcomes (16)
All- cause mortality
% of patients who die
Measured: 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.
Measured: 12 months
Appropriate shocks and patients with appropriate shocks
Rate over 12 months determined by IBHRE accredited Cardiac Scientist
Measured: 12 months
Inappropriate shocks and patients with inappropriate shocks
Rate over 12 months determined by IBHRE accredited Cardiac Scientist
Measured: 12 months
Complications
individually, defined as infections, bleedings, thrombotic events, pneumothorax, perforation/tamponade, lead reposition and lead- or device failures
Measured: 12 months
Cardiac decompensation
Measured by admissions for Heart failure or unplanned outpatient appointments.
Measured: 12 months
Crossovers to the other arm
Amount of patients moving from SICD to TV group and visa versa over 12 month period.
Measured: 12 months
Appropriate shock treatment in ATP or monitor zone
Rate over 12 months determined by IBHRE accredited Cardiac Scientist
Measured: 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.
Measured: 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.
Measured: 12 months
Cardiac (pre-) syncope events
rate of patients with these events over a 12 month period
Measured: 12 months
Time to successful therapy
Time in months or days from implant to date of succesful therapy
Measured: 12 months
First shock conversion efficacy
% of first shocks that cardiovert ventricular arrhythmia
Measured: 12 months
Implant procedure time
Duration of implant from needle to skin to skin closure.
Measured: Procedure duration- average of 2 hours expected
Hospitalization rate
Rate of patient hospitalisation for cardiac and non-cardiac causes over a 12 month period.
Measured: 12 months
Fluoroscopy time
Amount of fluoroscopy required to complete implant procedure, expected fluoroscopy time of approximately 1 minute per patient.
Measured: Procedure duration- average of 2 hours expected
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jul 2023
- Study start10 Jan 2024
- Primary completion7 Jan 2026
- Study completion7 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Implantable Defibrillator UserStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Pilot randomised control trial, randomised 1:1 for Transvenous: Subcutaneous
- Masking
- None (open label)
- Enrolment
- 5 participants (actual)
Sponsor and investigators
- Lead sponsor
- Barts & The London NHS Trust
- Sponsor type
- University, hospital or other
- Collaborators
- Boston Scientific Corporation, Queen Mary University of London
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05938283
- Sponsor's protocol ID
- 158953
- Acronym
- HICD
- Status last verified
- Feb 2026
- First submitted
- 13 Jun 2023
- Last updated
- 19 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 19 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pilot Study of Hypertrophic Cardiomyopathy & Implantable Cardioverter Defibrillator Assessment: (Subcutaneous vs Transvenous)
- ClinicalTrials.gov ID
- NCT05938283
- Acronym / sponsor ID
- HICD / 158953
- Conditions
- Implantable Defibrillator User, Hypertrophic Cardiomyopathy, Implantable Cardioverter Ventricular Lead Dysfunction or Complication, Ventricular Arrythmia
- Keywords
- Transvenous Implantable Defibrillator, Subcutaneous Implantable Defibrillator
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 5 participants (actual)
- Lead sponsor
- Barts & The London NHS TrustUniversity, hospital or other
- Collaborators
- Boston Scientific Corporation, Queen Mary University of London
- Study start
- 10 Jan 2024 (actual)
- Primary completion
- 7 Jan 2026 (actual)
- Study completion
- 7 Jan 2026 (actual)
- First posted
- 10 Jul 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Pilot randomised control trial, randomised 1:1 for Transvenous: Subcutaneous
| Arm | Type | Receives |
|---|---|---|
| Transvenous Implantable Defibrillator | Active comparator | Device: Implantable Cardioverter Defibrillator implantRoutine TV ICD implant |
| Subcutaneous Implantable Defibrillator | Active comparator | Device: Implantable Cardioverter Defibrillator implantSICD ICD implant as per study protocol |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Hypertrophic Cardiomyopathy and a referred for ICD therapy with no pacing requirement.
Key exclusion criteria (11 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Implantable Cardioverter Defibrillator implantICD implant to protect patients from life threatening ventricular tachycardia or ventricular fibrillation | Device | Subcutaneous Implantable Defibrillator, Transvenous Implantable Defibrillator |
Primary outcome
Rate of recruitment
Time frame: through study completion, expected at 10 months to 1 year
Assessment of rate of recruitment per month
Composite of inappropriate shock and ICD related complications
Time frame: 12 months
Rate of inappropriate shocks and ICD related complications across the patients over a 12 month period.
16 secondary outcomes
All- cause mortality
Time frame: 12 months
MACE events
Time frame: 12 months
Appropriate shocks and patients with appropriate shocks
Time frame: 12 months
Inappropriate shocks and patients with inappropriate shocks
Time frame: 12 months
Complications
Time frame: 12 months
Cardiac decompensation
Time frame: 12 months
Crossovers to the other arm
Time frame: 12 months
Appropriate shock treatment in ATP or monitor zone
Time frame: 12 months
Quality of life assessed by SF-36 survey
Time frame: 12 months
Quality of life assessed by EQ5D survey
Time frame: 12 months
Cardiac (pre-) syncope events
Time frame: 12 months
Time to successful therapy
Time frame: 12 months
First shock conversion efficacy
Time frame: 12 months
Implant procedure time
Time frame: Procedure duration- average of 2 hours expected
Hospitalization rate
Time frame: 12 months
Fluoroscopy time
Time frame: Procedure duration- average of 2 hours expected
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Feb 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Implantable Cardioverter Defibrillator implant in people with Implantable Defibrillator User and Hypertrophic Cardiomyopathy, run by Barts & The London NHS Trust at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of recruitment (time frame: through study completion, expected at 10 months to 1 year). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Feb 2026.