Outcomes of septal reduction surgery in paediatric hypertrophic cardiomyopathy in the United Kingdom (23 CONG 01)

University College London (UCL) requires access to NHS England data for the purpose of the following research project: Outcomes of septal reduction surgery in paediatric hypertrophic cardiomyopathy in the UK (23 CONG 01).

Left ventricular outflow tract obstruction (LVOTO) is present at rest in up to a third of children with hypertrophic cardiomyopathy (HCM) and is a common cause of symptoms. Surgical septal myectomy is indicated primarily for the relief of symptoms that are resistant to medical therapy but there are limited data available regarding the immediate and long-term outcomes of these patients. In adult cohorts, outcomes of surgical septal myectomy vary depending on centre volume but little is known of centre specific outcomes during childhood and previous reports have been limited by small numbers.

The following is a summary of the aims of the research project provided by UCL:

• To determine the number of septal myectomy surgeries being undertaken in children diagnosed with HCM in the UK.

• To determine the volume of septal myectomy surgeries being undertaken at individual cardiac centres across the UK.

• To describe the early and late outcomes of surgical LVOTO relief for children with Hypertrophic cardiomyopathy (HCM) in the United Kingdom:

. Proportion of patients readmitted to hospital within 30 days of undergoing myectomy surgery and the proportion of patients who die following myectomy surgery.

. Length of stay and survival to discharge following myectomy surgery.

. Frequency of complications and need for reoperation.

• To determine whether some children could benefit from receiving pharmaceutical therapy before proceeding to surgical relief of LVOTO.

The following NHS England Data will be accessed:

• Hospital Episode Statistics Admitted Patient Care – necessary because this will help determine the frequency of post-operative complications by investigating the number of patients readmitted to hospital within 30 days of their surgical procedure. This may also provide information relating to length of stay and will help to determine survival to discharge.

• Civil Registration of Deaths – necessary because this will help determine surgical risk by investigating the proportion of patients who die following this type of surgery and the length of time between surgical procedure and death.

National Congenital Heart Disease Audit (NCHDA) necessary to describe the early and late outcomes of surgical LVOTO relief for children with HCM in the United Kingdom.

The level of the Data will be

• Pseudonymised

The Data will be minimised as follows:

Limited to a study cohort identified by NHS England as meeting the following criteria:

- Limited to conditions relevant to the study identified by specific ICD or OPCS - codes; Patients diagnosed with Left ventricular outflow tract obstruction who have undergone Surgical septal myectomy.

- Limited to data between 01/01/2016 until 31/03/2024.

- Patients within England.

UCL is the research sponsor and the controller as the organisation responsible for ensuring that the Data will only be processed for the purpose described above.

The lawful basis for processing personal data under the UK GDPR is:

Article 6(1)(e) - processing is necessary for the performance of a task carried out in the public interest or in the exercise of official authority vested in the controller;

The processing is necessary for the performance of a task carried out in the public interest or in the exercise of official authority vested in the controller. The data provided will outline outcomes after surgery and influence decisions around service delivery in the NHS.

The lawful basis for processing special category data under the UK GDPR is:

Article 9(2)(j) - processing is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes in accordance with Article 89(1) based on Union or Member State law which shall be proportionate to the aim pursued, respect the essence of the right to data protection and provide for suitable and specific measures to safeguard the fundamental rights and the interests of the data subject.

This processing is in the public interest because it adheres to the UK Policy Framework for Health and Social Care Research, which protects and promotes the interests of patients, service users and the public, and aims to produce generalisable and publicly available information to inform future decisions over patients’ treatments or care.

The funding is provided by The National Institute of Health Research Great Ormond Street Hospital. The funding is specifically for the project described. Funding is in place until 31/03/2026.

The funder(s) will have no ability to suppress or otherwise limit the publication of findings.

Amazon Web Services (AWS) is a processor acting under the instructions of UCL. AWS’ role is limited to secure back-up of data stored in UCL’s Data Safe Haven.

Data will be accessed by substantive employees of UCL and two individuals with honorary contracts with UCL:

• Individuals holding an honorary contract under the supervision of a substantive employee of UCL for the purposes described in this DSA only. UCL must maintain records in a single location that cover the following details of each individual given access under an honorary contract:

. Their substantive employer;

. Their role in respect of the purpose for the processing specified in the DSA;

. The start date and end date of the duration in which the Data will be accessed by the individual under an honorary contract;

. The necessity for the Data to be accessed by the person(s) holding an honorary contract, instead of a substantive employee of an organisation named as controller or a processor in this DSA;

. Confirmation that an appropriate contract is in place which follows the relevant guidance and is countersigned by the substantive employer of the honorary contract holder.

The study team was recently involved with the Cardiomyopathy UK Priority Setting Partnership, in collaboration with the James Lind Alliance, working with a range of stakeholders to identify research priorities for cardiomyopathy. Amongst the top ten priorities were research into tailored treatment options and research into treatments preventing and stopping cardiomyopathy progression, both of which are relevant to the proposed research.

In focus groups recently undertaken by the research team with parents and young patients affected by HCM, participants have voiced a desire for research relating to prevention of disease progression, prevention of poor outcomes and reduction of risk. Patients and families have also expressed a desire for clear explanations about what is happening and why. This fits with the aims of this project to provide an evidence base for the future treatment of LVOTO in children with HCM.

This project was reviewed and supported by the NICOR Research Access Committee (RAC) on 10/03/2025.

NHS England will provide the relevant records from the Civil Registrations of Death dataset and HES APC to UCL. The Data will contain no direct identifying data items. The Data will be pseudonymised and individuals cannot be reidentified through linkage with other data in the possession of the recipient.

The Data will not be transferred to any other location.

The data will be stored on the UCL Data Safe Haven on servers at UCL. UCL uses offsite back-up services provided by VIRTUS Data Centres. UCL stores data on the Cloud provided by Amazon Web Services as contracted by UCL.

The Data will be accessed onsite at the premises of UCL only.

The Data will not leave England/Wales, at any time.

All personnel accessing the Data have been appropriately trained in data protection and confidentiality.

The Data will not be linked with any other data.

There will be no requirement and no attempt to reidentify individuals when using the Data.

Analysts from UCL will process the Data for the purposes described above.

The expected outputs of the processing will be:

A report of findings to the funder at the end of the project.

Submission of findings to peer reviewed journals (likely to be a single publication).

Presentation of findings at local meetings (UCL).

Presentations at speciality conferences (e.g.: British Congenital Cardiac Association, Association for European Paediatric and Congenital Cardiology, British Inherited Cardiovascular Conditions Society).

A document to support the review of service provision for paediatric hypertrophic cardiomyopathy in the UK.

The outputs will not contain NHS England Data and will only contain aggregated information with small numbers suppressed as appropriate in line with the relevant disclosure rules for the dataset(s) from which the information was derived.

Target date for outputs is January 2028.

• The findings are hoped to inform optimal service provision for children with HCM across the UK, allowing evidence-based decision making relating to the management of LVOTO.

• The findings are hoped determine whether there is any rationale for centralising surgical treatment of LVOTO in this patient group to improve clinical outcomes.

• The findings may enable improved identification of patients who can benefit from newly developed pharmaceutical therapies for LVOTO.

It is hoped that through publication of findings in appropriate journals and reports, the findings of this research will add to the body of evidence that is considered by the bodies, organisations and individual care practitioners charged with making policy decisions within the NHS or treatment decisions in relation to children diagnosed with obstructive HCM.

Specific outcomes and public benefits will be determined by the study findings, however this may include decision-making at a national level, relating to potential centralising of surgical myectomy provision for children in the UK to improve patient safety, or decision-making at a local level, relating to risk assessment treatment planning for individual patients.

Should the findings warrant further dissemination, existing links with national collaborators, networks and charities will be used to share these more widely.

Yielded Benefits is not a requirement for new applications.