An interventional study of Biofeedback intervention in Atrial Fibrillation (Paroxysmal), sponsored by Liverpool John Moores University. Recruiting at 1 site in United Kingdom. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-22.
Sponsored by Liverpool John Moores University · Not applicable, Interventional, and Supportive care
This project aims to bridge the gap between technology and healthcare by developing a biofeedback intervention that enables daily monitoring of atrial fibrillation episodes and physical activity levels. The main question it aims to answer is:
Is a co-designed, usability-tested, bio-feedback intervention aimed at nudging patients with paroxysmal atrial fibrillation to increase physical activity feasible for a larger randomised control trial?
The trial is split into two separate phases, each adopting different study designs, data collection, and data analysis methods.
Phase 1 Co-design and usability testing:
In this phase, we aim to test if smartwatches can be used to monitor AF and physical activity so that personalised atrial fibrillation-specific summaries can be created and sent to participants as text message nudges. The aim is to encourage participants to be more physically active.
Participants will wear a smartwatch for 3 weeks, during which they will receive text messages giving them feedback on their atrial fibrillation and physical activity. After the 3 weeks, all participants will take part in a workshop to provide feedback on what they thought and what could be improved. Improvements will be implemented by the researchers, and the process will repeat for a total of two iterations. On the first iteration only, participants will also be asked to wear a Holter monitor OR chest strap and an additional smartwatch for the first 24 hours, alongside an accelerometer watch for the first 7 days.
Phase 2 Feasibility study with embedded process evaluation:
This phase aims to assess whether it is feasible and acceptable to run a larger trial across the UK (i.e. can the intervention be delivered properly and do patients think it is useful).
Participants will be randomly allocated to either their normal standard of care, or to receive a smartwatch with the biofeedback messaging service in addition to their normal standard of care. The study will take 6 and a half months in total. Both groups will complete online questionnaires periodically over this period. Both groups will also need to wear a smartwatch and accelerometer watch for 7 days before and after testing.
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 40 is below the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Liverpool John Moores University is the lead sponsor of 75 studies on the registry; 13 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
If allocated to the intervention group, you will be sent a smartwatch and device introduction pack with information on how to download a custom mobile application named Motivate-cloud and the Polar Flow mobile application, with instructions on how to sync your Polar device. Once set up, you will wear the smartwatch device for 6-months that records heart rate and physical activity. During this time, you will be sent regular text messages with motivating information on your activity (steps, time sitting, standing and moving) and AF. \*Important note: when we send you messages regarding your risk of AF, this is based on your heart rate variability (i.e. the variation in time between heart beats), and based on this variation, we predict we can determine whether the risk of being in AF has gone up or down for a given period of time.\*
Behavioral: Biofeedback intervention
You would have had a conversation about the benefits of lifestyle and physical activity with your direct health care team prior to agreeing to receiving contact with the research team. If you are allocated to this group, you will continue with usual medical treatment for your atrial fribrillation as determined by your healthcare team. You will receive adequate information and support, lifestyle advice about smoking, exercise, diet, and weight control.
Participants wearing a smartwatch will receive feedback on their paroxysmal atrial fibrillation and physical activity. This feedback will hopefully nudge them to become more physically active.
Phase 1: Co-design biofeedback nudges and report content, layout and the optimal time/frequency of nudges. Underpinned by a double diamond framework, through an iterative co-design process.
1\) Patients' qualitative data (workshops and/or 1:1 feedback meetings) investigating nudges and report: A) Content B) Layout C) Delivery Intervals
Time frame: Immediately after the 3-week usability testing iterations.
Phase 1: Co-design biofeedback nudges and report content, layout and the optimal time/frequency of nudges. Underpinned by a double diamond framework, through an iterative co-design process.
2\) Participants' reflection/feedback via user diaries.
Time frame: During each 3-week usability testing period.
Phase 2: Determine the number of patients identified, screened, appraoched eligable, consented, completed the trial, withdrew from the trial, and adherence to the trial.
Outcome measure: Information will be collected on: 1. The number of patients screened, eligible and approached. 2. The percentage of patients that: A) Decline the biofeedback intervention (including reasons for declining). B) Agree to the biofeedback intervention. C) Consent to being part of the study. 3. The percentage of patients that take up the biofeedback intervention and reasons for drop out. 4. The percentage of participants that complete outcome assessments and reasons for drop out. 5. The percentage time individuals wear the devices.
Time frame: Through study recruitment and all data collection, an average of 2 years.
Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention
1\) Multidisciplinary stakeholder groups including the research team and patients' qualitative data (workshops and/or 1:1 feedback meetings) investigating: A) General usability and acceptability. B) Faults or problem identification. C) Intervention delivery optimisation.
Time frame: Immediately after the 3-week usability testing iterations
Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention
2\) Participants reflection / feedback via user diaries.
Time frame: During each 3-week usability testing period.
Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention
3\) Researcher observations
Time frame: Through study recruitment and data collection, an average of 4 months
Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention
4\) Systems usability scale (SUS) questionnaire during the first co-design workshop. Scored from 0-100. Higher score = better usability (outcome).
Time frame: Immediately after the first 3-week usability testing iteration.
Phase 1: Quantify the time taken and resources required to produce nudges to gain an understanding of the maximum potential active intervention participants that can be simultaneously ongoing in Phase-2 feasibility RCT
Information will be collected on: 1\) The average time taken to produce each nudge (measured from accessing patient account to sending item). A) Any identified issues with the intervention (via researcher diary).
Time frame: Through study recruitment and data collection, an average of 4 months
Phase 1: Investigate the validity and quantify the error of the Polar Pacer smartwatch HRV data against a clinical-grade Holter monitor, or the Polar H10 chest strap.
1\) Continuous HRV data from both devices simultaneously to evaluate: A) Validity and reliability of the Polar Pacer HRV data. B) Error associated with Polar Pacer HRV data. C) Measurement error at each MET threshold. D) Optimal MET threshold cut off for HRV (risk of AF) analysis. E) Considerations for any future validation studies.
Time frame: First 24-hour periprocedural period.
Phase 1: Investigate the reliability and quantify the error of the Polar Pacer activity score as a measurement of PA against the GENEactiv wrist-based accelerometer
1\) Simultaneous collection of accelerometer and PA data from both devices to evaluate: A) Reliability of the Polar Pacer activity score as a measure of PA. B) PA measurement error of the Polar Pacer. C) Considerations for any future validation studies.
Time frame: First 7-days of periprocedural period.
Phase 2: 2) Evaluate the acceptability of the intervention to patients, assessing the feasibility of delivering the biofeedback intervention to patients with paroxysmal AF
Qualitative acceptability assessment through topic-guided semi-structured 1:1 interviews post-intervention, investigating: 1. The acceptability of the intervention components and barriers and facilitators to the intervention. 2. Acceptability of the study design and process (recruitment, randomisation, remote design) 3. Acceptability of the measurement instruments.
Time frame: Within 1 month of completing all 6-month post-intervention data collection.
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.1) Physical activity (steps) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer steps additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.2) Physical activity (time spent sleeping) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent sleeping additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.3) Physical activity (time spent sitting) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent sitting additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.4) Physical activity (time spent standing) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent standing additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.5) Physical activity (time spent in light activity) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent in light activity additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.6) Physical activity (time spent in moderate activity) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent in moderate activity additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.7) Physical activity (time spent in vigorous activity) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent in vigorous activity additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.8) Physical activity (calories) measured via Polar Pacer smartwatch
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer calories additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
1.9) Physical activity (total METs) measured via Polar Pacer smartwatch.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer total METs additionally measured throughout 6-month intervention).
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
2\) Health-related quality of life via the AF Effect on quality of life (AFEQT) scale. Scored from 0-100. Higher score = best possible quality of life.
Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
3\) EuroQol, 5 Dimensions, 5 Levels of severity (EQ-5D-5L) questionnaire. Responses are combined into a 5-digit code, ranging from 11111 (perfect health) to 55555 (worst health). This 5-digit code is converted into a weighted index score that represents the societal value of that health state. A score of 1.000 represents full health.
Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
4\) 12-Item Short Form Survey (SF-12). Measures physical and mental components of health, with each question carrying a different weighting. Norm-based scoring is used, allowing comparison to the general US population. A score of 50 is considered average health, with higher values indicating better health.
Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
5\) AF symptom severity via the University of Toronto Atrial Fibrillation Symptom Severity (AFSS) questionnaire. Scores range from 0-35. Higher score indicate more severe symptoms.
Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)
Phase 2: Assess the suitability of outcome measures for future full-scale RCT.
6\) HRV (risk of AF) measured as % time with a risk of AF and number of episodes.
Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer HRV additionally measured throughout 6-month intervention).
Plan to share: Undecided
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