NIRA-HOCM
Research type
Research Study
Full title
Non-invasive radiation ablation for septal reduction in patients with hypertrophic obstructive cardiomyopathy.
IRAS ID
255462
Contact name
Constantinos O'Mahony
Contact email
Sponsor organisation
Barts Health NHS Trust
Duration of Study in the UK
3 years, 0 months, 1 days
Research summary
Hypertrophic cardiomyopathy (HCM) is a common disease of the heart which causes thickening of the heart muscle. HCM primarily affects the muscle of the main pumping chamber of the heart (the left ventricle) and particularly the septum (this is the muscular wall which separates the right and left side of the heart). In a subgroup of patients, the thickened heart muscle at the septum prevents blood from leaving the heart during contraction (this is called obstruction). This form of the disease is called hypertrophic obstructive cardiomyopathy (HOCM).
HOCM is a common cause of shortness of breath, chest pain and dizzy spells. These symptoms are treated with tablets and if symptoms are uncontrolled, patients are often offered invasive treatment to get rid of some of the thick heart muscle and reduce obstruction. This is achieved either by:
1) open heart surgery (myectomy) where a surgeon cuts out the thick muscle
2) injection of alcohol to the thick heart muscle via a tube in the wrist or groin (alcohol septal ablation). The alcohol thins the heart muscle at the point of obstruction, mimicking the effects of myectomy.Unfortunately, some patients are not suitable for both these procedures.
This study will test whether radiotherapy, usually used for the treatment of tumours, can be used to destroy the thick heart muscle at the point of obstruction safely and effectively. Study patients will be monitored following the procedure and we plan to measure the levels of heart muscle thinning, reduction of obstruction and improvement in symptoms and importantly document any side effects.
Radiotherapy works by precisely targeting high energy X-rays (ionising radiation) at a specific area of the body with the aim of destroying abnormal tissue. CyberKnife is one of the latest radiotherapy delivery systems, which will deliver highly focussed and accurate radiotherapy.
Lay Summary of Results
The aim of this project was to evaluate the effectiveness of using stereotactic body radiation therapy (SBRT) with the CyberKnife platform as a non-invasive treatment for patients with Hypertrophic Obstructive CardioMyopathy (HOCM). The primary goal was to determine if this new method is safe and could reduce left ventricular outflow tract obstruction (LVOTO) in patients who have not responded to other conventional treatments. The research project was undertaken at St Bartholomew’s Hospital.
In this pilot study one patient was treated with SBRT, and the radiotherapy was delivered appropriately to the thick heart muscle. However, imaging of the heart demonstrated that the treated heart muscle did not become thinner, LVOTO persisted and symptoms did not abate (with a transient exacerbation).
Five years after the inception of the study the therapeutic landscape of LVOTO was transformed by the availability of cardiac myosin inhibitors such as Mavacamten whose efficacy has limited the pool of eligible patients for SBRT. On this basis the study was terminated.
Has the registry been updated to include summary results?: No
If yes - please enter the URL to summary results:
If no – why not?: Will be updated by the end of March 2025
Did you follow your dissemination plan submitted in the IRAS application form (Q A51)?: Pending
If yes, describe or provide URLs to disseminated materials:
If pending, date when dissemination is expected: 25/08/2025
If no, explain why you didn't follow it:
Have participants been informed of the results of the study?: Yes
If yes, describe and/or provide URLs to materials shared and how they were shared: Informed patient she was part of the study and study prematurely stopped because five years after the inception of the study the therapeutic landscape of LVOTO was transformed by the availability of cardiac myosin inhibitors such as Mavacamten whose efficacy has limited the pool of eligible patients for SBRT. On this basis the study was terminated. Patients routine clinical care will continue.
If pending, date when feedback is expected:
If no, explain why they haven't:
Have you enabled sharing of study data with others?: No
If yes, describe or provide URLs to how it has been shared:
If no, explain why sharing hasn't been enabled: Study did not complete. Clinicaltrials.gov will be updated
Have you enabled sharing of tissue samples and associated data with others?: No
If yes, describe or provide a URL:
If no, explain why: Study did not complete. Clinicaltrials.gov will be updatedREC name
London - Stanmore Research Ethics Committee
REC reference
19/LO/1619
Date of REC Opinion
9 Dec 2019
REC opinion
Further Information Favourable Opinion