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

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

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

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.

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).