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NCT Number: NCT07454317

Biofeedback Intervention for Paroxysmal Atrial Fibrillation

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.

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Key information

Conditions

Atrial Fibrillation (Paroxysmal) Arrhythmias, Cardiac Atrial Fibrillation Behavior Cardiovascular Diseases Heart Diseases Motor Activity Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Liverpool John Moores University

Liverpool, Merseyside, L3 3AF, United Kingdom

Location status: Recruiting

Location contact

Luca J Howard

CONTACT

[email protected]

+44 151 231 2121

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participant is willing and able to give informed consent for participation in the study.
  • Aged 18 or over.
  • Diagnosed with paroxysmal AF
  • Deemed medically stable and well managed.

Exclusion criteria

  • Any concurrent cardiac arrhythmia
  • Blood pressure >180/100
  • Unstable angina
  • Myocardial infarction within the previous 3 months
  • Valvular heart disease
  • Heart failure NYHA class 4
  • <6 months post-transplant
  • Resting/uncontrolled tachycardia
  • Stroke in last 6 weeks
  • Cardiac sarcoidosis
  • Injury or disability preventing exercise

Treatment and study plan

Biofeedback intervention

Behavioral

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.

Primary outcomes

  1. 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.

    Time frame: Immediately after the 3-week usability testing iterations.

    • Patients' qualitative data (workshops and/or 1:1 feedback meetings) investigating nudges and report: A) Content B) Layout C) Delivery Intervals

  2. 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.

    Time frame: During each 3-week usability testing period.

    • Participants' reflection/feedback via user diaries.

  3. Phase 2: Determine the number of patients identified, screened, appraoched eligable, consented, completed the trial, withdrew from the trial, and adherence to the trial.

    Time frame: Through study recruitment and all data collection, an average of 2 years.

    Outcome measure:

    Information will be collected on:

    • The number of patients screened, eligible and approached.
    • 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.

    • The percentage of patients that take up the biofeedback intervention and reasons for drop out.
    • The percentage of participants that complete outcome assessments and reasons for drop out.
    • The percentage time individuals wear the devices.

Secondary outcomes

  1. Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention

    Time frame: Immediately after the 3-week usability testing iterations

    • 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.

  2. Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention

    Time frame: During each 3-week usability testing period.

    • Participants reflection / feedback via user diaries.

  3. Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention

    Time frame: Through study recruitment and data collection, an average of 4 months

    • Researcher observations

  4. Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention

    Time frame: Immediately after the first 3-week usability testing iteration.

    • Systems usability scale (SUS) questionnaire during the first co-design workshop. Scored from 0-100. Higher score = better usability (outcome).

  5. 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

    Time frame: Through study recruitment and data collection, an average of 4 months

    Information will be collected on:

    • 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).

  6. 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.

    Time frame: First 24-hour periprocedural period.

    • 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.

  7. 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

    Time frame: First 7-days of periprocedural period.

    • 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.

  8. Phase 2: 2) Evaluate the acceptability of the intervention to patients, assessing the feasibility of delivering the biofeedback intervention to patients with paroxysmal AF

    Time frame: Within 1 month of completing all 6-month post-intervention data collection.

    Qualitative acceptability assessment through topic-guided semi-structured 1:1 interviews post-intervention, investigating:

    • The acceptability of the intervention components and barriers and facilitators to the intervention.
    • Acceptability of the study design and process (recruitment, randomisation, remote design)
    • Acceptability of the measurement instruments.

  9. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer steps additionally measured throughout 6-month intervention).

    1.1) Physical activity (steps) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  10. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent sleeping additionally measured throughout 6-month intervention).

    1.2) Physical activity (time spent sleeping) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  11. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent sitting additionally measured throughout 6-month intervention).

    1.3) Physical activity (time spent sitting) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  12. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer time spent standing additionally measured throughout 6-month intervention).

    1.4) Physical activity (time spent standing) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  13. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    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).

    1.5) Physical activity (time spent in light activity) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  14. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    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).

    1.6) Physical activity (time spent in moderate activity) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  15. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    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).

    1.7) Physical activity (time spent in vigorous activity) measured via Polar Pacer smartwatch and GENEactiv wrist-based accelerometer.

  16. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer calories additionally measured throughout 6-month intervention).

    1.8) Physical activity (calories) measured via Polar Pacer smartwatch

  17. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer total METs additionally measured throughout 6-month intervention).

    1.9) Physical activity (total METs) measured via Polar Pacer smartwatch.

  18. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)

    • 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.

  19. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)

    • 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.

  20. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)

    • 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.

  21. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 4 timepoints: Baseline (pre-intervention), month-1, month-3 and month-6 (post-intervention)

    • 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.

  22. Phase 2: Assess the suitability of outcome measures for future full-scale RCT.

    Time frame: 7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer HRV additionally measured throughout 6-month intervention).

    • HRV (risk of AF) measured as % time with a risk of AF and number of episodes.

Study contacts

Contact information is provided by the study sponsor or research team.

Benjamin Buckley

CONTACT

[email protected]

0151 231 2121

Luca J Howard

CONTACT

[email protected]

+ 151 231 2121

Sponsors and collaborators

Lead sponsor

Liverpool John Moores University

Other

Collaborators

  • Liverpool Heart and Chest Hospital NHS Foundation Trust

Registry information

Official study title

Remote Physical Activity Biofeedback Intervention for Patients With Paroxysmal Atrial Fibrillation Using Mobile Health Technology.

Acronym: BI-PAF

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Mar 6, 2026
Registry last updated
May 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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