Investigating changes in brain networks and cognition after heart surgery
| ISRCTN | ISRCTN68065962 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN68065962 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | N/A |
| Sponsor | University Hospitals Bristol NHS Foundation Trust |
| Funder | Above and Beyond (Registered Charity Number: 229945) |
- Submission date
- 28/06/2018
- Registration date
- 08/08/2018
- Last edited
- 03/10/2024
- Recruitment status
- Stopped
- Overall study status
- Stopped
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Cognitive impairment is common after cardiac (heart) surgery, particularly in older people. Up to six in every 10 patients who undergo cardiac surgery have some degree of cognitive impairment six months after their surgery. The mechanisms involved are unclear. Recent research in brain imaging has identified some regions of the brain involved in learning and memory which are working when the brain is “at rest”, that is when the subject is not performing an explicit cognitive task. These brain networks, so called “resting state networks”, represent the baseline, or default, mode of the brain. Brain imaging studies have shown that when the activity of resting state networks is reduced, patients are more likely to develop cognitive impairment. There is currently limited evidence to suggest whether cardiac surgery causes damage to resting state networks thus leading to cognitive impairment. This study will investigate changes in resting state networks in 20 patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) using functional brain magnetic resonance imaging (fMRI). This study will help doctors to better understand the mechanisms leading to cognitive impairment following cardiac surgery and will aid in the development of preventive strategies and new treatments.
Who can participate?
Patients aged between 60 and 75 undergoing coronary artery bypass surgery (CABG) with CPB at the Bristol Heart Institute
What does the study involve?
All patients undergo two fMRI scans and cognitive assessments. The first scan and cognitive assessments take place around 1 week before their heart surgery and the second around 6 weeks after surgery. Each fMRI scan takes about 40 minutes. The cognitive tests take around 45 minutes and assess memory, coordination and levels of attention.
What are the possible benefits and risks of participating?
There are no direct benefits of participating in this study. This study of the potential role of default mode networks in CPB-related cognitive decline could aid the development of interventions to improve neurocognitive outcomes following surgery, such as cognitive training and physical exercise. There are no associated risks with functional MRI or the neurocognitive assessments.
Where is the study run from?
University Hospitals Bristol NHS Foundation Trust (UK)
When is the study starting and how long is it expected to run for?
April 2018 to March 2020
Who is funding the study?
Above and Beyond (UK)
Who is the main contact?
Mr Jonathan Evans
codec-study@bristol.ac.uk
Contact information
Public
Clinical Trials and Evaluation Unit
Bristol Royal Infirmary, Level 7
Marlborough Street
Bristol
BS2 8HW
United Kingdom
| Phone | +44 (0)117 342 2374 |
|---|---|
| codec-study@bristol.ac.uk |
Scientific
Clinical Trials and Evaluation Unit
Bristol Royal Infirmary, Level 7
Marlborough Street
Bristol
BS2 8HW
United Kingdom
| Phone | +44 (0)117 342 2526 |
|---|---|
| codec-study@bristol.ac.uk |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Single-centre observational study |
| Secondary study design | |
| Study type | Participant information sheet |
| Scientific title | Investigation of neural mechanisms of COgnitive DEcline after Cardiac surgery with resting state fMRI (CODEC): a pilot study |
| Study acronym | CODEC |
| Study objectives | The primary hypothesis is that default mode network connectivity is impaired following coronary artery bypass graft surgery with cardiopulmonary bypass and correlates with neurocognitive testing. |
| Ethics approval(s) | Approved 03/12/2018, London - Hampstead Research Ethics Committee (Barlow House 3rd Floor, 4 Minshull Street, Manchester M1 3DZ; 0207 104 8345; NRESCommittee.London-Hampstead@nhs.net), ref: 18/LO/2121 |
| Health condition(s) or problem(s) studied | Cardiac disease/coronary artery bypass grafting |
| Intervention | Patients who consent will be required to undergo two functional MRI scans and neuro-cognitive assessments. Patients will have the first scan and neuro-cognitive assessments pre-surgery (1- 8 weeks before surgery date). The second scan and assessments will take place post-surgery (5-10 weeks post surgery date). Each fMRI scan will take approximately 40 minutes. The scans will take place at the Bristol Clinical Research and Imaging Centre. The neuro-cognitive assessment involves tests that assess memory, coordination and levels of attention. As part of the assessment patients will also complete two questionnaires examining current mood/emotional state. Each neuro-cognitive assessment will take approximately 45 minutes. |
| Intervention type | Other |
| Primary outcome measure(s) |
The change from baseline in default mode network connectivity in the brain post cardiac surgery as assessed by resting state fMRI performed 5-10 weeks post operatively |
| Key secondary outcome measure(s) |
1. Change from baseline in cognitive ability as assessed by standard neurocognitive tests administered 5- 10 weeks post operatively |
| Completion date | 09/02/2021 |
| Reason abandoned (if study stopped) | Lack of staff/facilities/resources |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Senior |
| Sex | All |
| Target sample size at registration | 20 |
| Key inclusion criteria | 1. Aged between 60-75 years 2. Electively referred for isolated coronary artery bypass grafting |
| Key exclusion criteria | 1. Prisoners and adults lacking capacity to consent 2. Contraindications to MR (implanted electronic devices, metallic foreign bodies, claustrophobia, body weight >140 kg or waist perimeter exceeding manufacturer's recommendations and others according to manufacturer’s recommendations and generally accepted guidelines) 3. Patients with a neurological disorder (e.g. epilepsy, Alzheimer’s, dementia and Parkinson’s disease) 4. Patients with a diagnosed psychiatric disorder (e.g. schizophrenia, psychosis), drug or alcohol addiction 5. Patients with an already identified as having cognitive impairment (e.g. memory and/or attentional deficits) as defined by psychometric assessment or a preoperative Mini-mental State Examination score < 24. The Mini-mental State Examination will be adminstered after consent but prior to any of the cognitive assessements or fMRI scan 6. Patients who have previously sustained a stroke, intra-cerebral haemorrhage, acquired brain injury 7. Patients unable to complete the cognitive assessments required for the trial e.g. due to language difficulties, visual or hearing impairment |
| Date of first enrolment | 15/04/2019 |
| Date of final enrolment | 01/12/2020 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
Bristol
BS1 3NU
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | Current IPD sharing statement as of 11/07/2019: Anonymised individual patient data (baseline, operative, outcome data and adverse events) will be made available for secondary research, conditional on assurance from the secondary researcher that the proposed use of the data is compliant with the MRC Policy on Data Preservation and Sharing regarding scientific quality, ethical requirements and value for money. Please contact Prof. Chris Rogers (chris.rogers@bristol.ac.uk) to discuss any data requests. Data will be made after the study has been closed and the primary publication is out. It will be made available indefinitely. The patient information leaflet which participants consent to explains that we will only share information collected in this study with the participants' agreement. The consent form includes the following question ‘I give permission for data collected as part of this study to be used in future ethically approved studies’. Previous IPD sharing statement: Anonymised individual patient data (baseline, operative, outcome data and adverse events) will be made available for secondary research, conditional on assurance from the secondary researcher that the proposed use of the data is compliant with the MRC Policy on Data Preservation and Sharing regarding scientific quality, ethical requirements and value for money. Please contact Prof. Chris Rogers (chris.rogers@bristol.ac.uk) to discuss any data requests. Data will be made after the study has been closed and the primary publication is out. It will be made available indefinitely. The patient information leaflet which participants consent to explains that data may be provided to researchers running other research studies. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| HRA research summary | 28/06/2023 | No | No | ||
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
03/10/2024: The study was abandoned on 04/06/2020 due to the CI leaving their institution.
22/10/2021: Internal review.
09/01/2020: The following changes were made to the trial record:
1. The contact details were updated.
2. The recruitment end date was changed from 15/12/2019 to 01/12/2020.
3. The overall trial end date was changed from 01/03/2020 to 09/02/2021.
4. The intention to publish date was changed from 30/10/2020 to 09/04/2021.
11/07/2019: The following changes were made:
1. The ethics approval was updated.
2. The IPD sharing statement was updated.
17/04/2019: The following changes were made to the trial record:
1. The recruitment start date was changed from 10/09/2018 to 15/04/2019.
2. The recruitment end date was changed from 10/06/2019 to 15/12/2019.
3. The overall trial end date was changed from 30/10/2019 to 01/03/2020.
