Pacemaker therapy for drug-refractory symptoms in mid-cavity hypertrophic cardiomyopathy

ISRCTN ISRCTN82621856
DOI https://doi.org/10.1186/ISRCTN82621856
ClinicalTrials.gov number NCT03450252
Secondary identifying numbers 36358
Submission date
03/01/2018
Registration date
11/01/2018
Last edited
07/11/2024
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Hypertrophic cardiomyopathy (HCM) is the most common familial heart disease, affecting one in five hundred of the general population. It involves abnormal thickening of the heart in absence of other reasonable causes such as heart valve disease, and the various patterns of thickening mean blood flow within the heart is often abnormal. Obstruction to blood flow out into the main artery (the aorta) is often present at a level below that of the aortic valve, and this can place extra strain upon the heart muscle. This extra strain means patients frequently suffer from symptoms such as shortness of breath and chest pain, poor exercise tolerance, or dizzy spells. Around 60% of HCM patients will have obstruction to blood flow at the base of the heart, at the level of the mitral valve, and there are several invasive therapies to consider as treatment if treatment with medicine is failing to reduce symptoms. However, in a smaller group of around one in ten HCM patients, obstruction to blood flow occurs in a different area, within the middle of the left heart. These patients provide a challenge for management, as they are less suitable for invasive treatment options. Using a pacemaker to excite the heart in patients with obstruction within the middle of the heart has been demonstrated to reduce the obstruction and importantly improve patient symptoms. The aims of this study are to find out how effective cardiac pacing is at reducing obstruction in the middle of the heart, and to see whether this leads to an improvement in symptoms.

Who can participate?
Patients aged over 18 undergoing implantation of a pacemaker

What does the study involve?
Participants undergo an assessment and pacemaker implantation. They are randomly allocated to have the pacemaker set up to pace all the time (active pacing) or back-up pacing only (very little pacing) for 24±2 weeks. At 24±2 weeks their symptoms and physical performance are assessed at a visit to the hospital and they then have the pacemaker switched to the other setting for another 24±2 weeks (either active pacing or back-up pacing depending on which they had first). Participants are assessed again at 48±2 weeks.

What are the possible benefits and risks of participating?
It cannot be guaranteed that a patient’s symptoms will improve as part of this study. However, patients with the condition have very few treatment options available to them if medication doesn’t ease their symptoms. Early tests of using a pacemaker for the condition have been very encouraging, so this study may lead to larger studies that change how patients are treated all over the world with the specific heart condition. Significant side effects are not expected as part of the study. If patients feel unwell for any reason they can get in contact with the research team. If any unexpected health-related findings are discovered as part of this study, they will be shared appropriately with the patient and the clinical team responsible for their care.

Where is the study run from?
St Bartholomew’s Hospital (UK)

When is the study starting and how long is it expected to run for?
June 2017 to May 2022 (updated 10/05/2021, previously: May 2021)

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Dr Saidi Mohiddin

Contact information

Dr Saidi Mohiddin
Scientific

Barts Heart Centre
No 1 St Martins Le Grand
London
EC1A 4AS
United Kingdom

ORCiD logoORCID ID 0000-0002-1031-4084

Study information

Study designRandomised; Interventional; Design type: Treatment, Complex Intervention
Primary study designInterventional
Secondary study designRandomised cross over trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet ISRCTN82621856_PIS_V6_01Dec17.pdf
Scientific titleDistal ventricular pacing and intraventricular gradient reduction for symptomatic relief in drug-refractory hypertrophic cardiomyopathy patients with mid-cavity obstruction
Study objectivesHypertrophic cardiomyopathy (HCM) is the most common familial heart disease, affecting one in five hundred of the general population. Characterised by abnormal thickening of the heart in absence of other reasonable causes such as heart valve disease, the various patterns of thickening mean blood flow within the heart is often abnormal. Obstruction to blood flow out into the main artery, the aorta, is often present at a level below that of the aortic valve, and this can place extra strain upon the heart muscle.

This extra strain means patients frequently suffer from debilitating symptoms such as shortness of breath and chest pain, poor exercise tolerance, or dizzy spells. Around 60% of HCM patients will have obstruction to blood flow at the base of the heart, at the level of the mitral valve, and there are several invasive therapies to consider as treatment if treatment with medicine is failing to reduce symptoms. However, in a smaller group of around one in ten HCM patients, obstruction to blood flow occurs in a different area, within the middle of the left heart. These patients provide a challenge for management, as they are less suitable for invasive treatment options.

Using a pacemaker to excite the heart in patients with obstruction within the middle of the heart has been demonstrated to reduce the obstruction and importantly improve patient symptoms, and this is supported by our pilot data. The research questions to be addressed are: How effective is cardiac pacing at reducing obstruction in the middle of the heart? The second question is does this lead to symptomatic benefit for the patient?
Ethics approval(s)London Harrow Research Ethics Committee, 06/12/2017, ref: 17/LO/1725
Health condition(s) or problem(s) studiedHypertrophic cardiomyopathy
InterventionPatients will be identified in outpatient cardiomyopathy clinics, with initial screening and eligibility assessment made by a researcher. A trained member of the research team will take informed consent in the cardiac department at Barts Heart Centre. Recruited subjects will then attend for baseline assessment by a researcher and performance testing over one encounter.

A member of the research team shall direct the participant to fill out the Kansas City Cardiomyopathy questionnaire and the SF36 questionnaire in a private office without interruption. The six-minute walk test shall be performed in the cardiac department by a member of the cardiac physiology team, as per standard care. Cardiac Magnetic Resonance Imaging (MRI) will be done in the imaging department at Barts Heart Centre, performed by the imaging team and reviewed by a consultant cardiologist. Cardiopulmonary exercise testing with simultaneous echocardiography (stress echo) shall take place in the cardiac department and be performed by a member of the cardiac physiology team along with members of the research team as necessary. A small blood sample (~5 mL) shall be taken in the cardiac department at each study visit for analysis of the protein brain natriuretic peptide. The sample shall be taken from venous cannulation performed by a trained individual.

There is a further attendance for device implantation and invasive haemodynamic pacing study. A trial randomisation service (such as https://www.sealedenvelope.com or www.randomize.net) will be used to assign participants to one of the cross over arms initially. One group will have the pacemaker set up to pace all the time (active pacing), and one group will be set up for back-up pacing only (very little pacing) for 24±2 weeks. The pacemaker implant shall be performed in the catheter labs of Barts Heart Centre, by a consultant cardiologist. Adjustments to pacemaker settings shall occur at the visits to the cardiac department at Barts Heart Centre. They shall be performed by a member of the cardiac physiologist team who is qualified to do so. At 24±2 weeks the patients' symptoms and physical performance will be assessed at a visit to the hospital and they will then have the pacemaker switched to the other setting for another 24±2 weeks (either active pacing or back-up pacing depending on which they had first). Patients will then be assessed again at 48±2 weeks. The length of each treatment phase is longer than previous pacemaker studies at 24 weeks in order to account for any wash-out periods, which have historically been a criticism of cross-over trial designs.
Intervention typeDevice
Pharmaceutical study type(s)
PhasePhase II/III
Drug / device / biological / vaccine name(s)Not provided at time of registration
Primary outcome measureDirect measurement of obstructive gradient (mmHg) via intracardiac catheter during pacemaker implant; Timepoint(s): During implant
Secondary outcome measuresThe feasibility of performing a cross-over study and the associated performance tests and symptomatic assessments in this patient population. The statistical information collected will be used to design a much larger research trial of patient benefit.
Overall study start date01/06/2017
Completion date31/05/2022

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participantsPlanned Sample Size: 25; UK Sample Size: 25
Key inclusion criteria1. Male or female, >18 years
2. Referred for PPM +/- ICD implantation for either primary prevention of sudden cardiac death or other indications such as heart block or obstructive physiology
3. HCM patients with a mid-cavity gradient of ≥30 mmHg demonstrated by echocardiography and morphology confirmed by cardiac MRI. Gradient confirmed by cardiac catheterisation
4. All patients should be taking maximum tolerated doses of beta blockers or verapamil with or without disopyramide
5. Symptoms refractory to optimum medical therapy as above, for example breathlessness, chest pain, dizziness, or syncope
Key exclusion criteria1. Patients with multi-level obstruction, i.e. across the mid-cavity and outflow tract
2. Patients with moderate or severe valvular stenosis or regurgitation due to primary valvular disease
3. Patients with untreated symptomatic coronary disease
4. Patients in atrial fibrillation at the time of implantation
5. Pregnancy
6. Renal failure with eGFR < 20mL/min
7. Any patient not suitable in the clinicians opinion
8. Any patient who is for whatever reason is not expected for more than one year
9. Patients unable to provide informed consent
Date of first enrolment01/02/2018
Date of final enrolment31/03/2022

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

St Bartholomew’s Hospital
Barts Heart Centre
London
EC1A 7BE
United Kingdom

Sponsor information

Queen Mary University of London
University/education

c/o Dr Sally Burtles
Director of Research Services & Business Development (JRMO)
QM Innovation Centre, 5 Walden Street
Whitechapel
London
E1 2EF
England
United Kingdom

ROR logo "ROR" https://ror.org/026zzn846

Funders

Funder type

Government

NIHR Trainees Co-ordinating Centre (TCC); Grant Codes: ICA-CDRF- 2016-02- 068

No information available

Results and Publications

Intention to publish date31/05/2023
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
Publication and dissemination planProject results will be submitted for publication in peer-reviewed journals (e.g. European Heart Journal, Journal of the American College of Cardiology), irrespective of outcome, within 12 months of completion.
IPD sharing planThe data sharing plans for the current study are unknown and will be made available at a later date.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Participant information sheet version V6 01/12/2017 11/01/2018 No Yes
Protocol file version V9 09/11/2017 11/01/2018 No No
HRA research summary 28/06/2023 No No

Additional files

ISRCTN82621856_PIS_V6_01Dec17.pdf
Uploaded 11/01/2018
ISRCTN82621856_PROTOCOL_V9_09Nov17.pdf
Uploaded 11/01/2018

Editorial Notes

07/11/2024: Internal review.
20/09/2021: Internal review.
10/05/2021: The following changes were made to the trial record:
1. The recruitment end date was changed from 31/03/2020 to 31/03/2022.
2. The overall end date was changed from 31/05/2021 to 31/05/2022.
3. The intention to publish date was changed from 31/05/2022 to 31/05/2023.
4. The plain English summary was updated to reflect these changes.
13/07/2020: The trial contact details have been made publicly visible.
06/04/2020: Due to current public health guidance, this study has been paused.
12/03/2020: The recruitment end date was changed from 29/02/2020 to 31/03/2020.
16/01/2020: ClinicalTrials.gov number added.
29/03/2019: The condition has been changed from "Specialty: Cardiovascular disease, Primary sub-specialty: Cardiac Surgery; UKCRC code/ Disease: Cardiovascular/ Other forms of heart disease" to "Hypertrophic cardiomyopathy" following a request from the NIHR.
01/03/2019: Internal review.
11/01/2018: Uploaded protocol Version 9 09 November 2017 (not peer-reviewed).