Biofeedback Intervention for Paroxysmal Atrial Fibrillation (BI-PAF)

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

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.

Study Overview

• Status: Recruiting
• Conditions: Atrial Fibrillation (Paroxysmal)
• Intervention / Treatment: Behavioral: Biofeedback intervention

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Benjamin Buckley; Phone Number: 0151 231 2121; Email: B.J.Buckley@ljmu.ac.uk
• Study Contact Backup: Name: Luca J Howard; Phone Number: + 151 231 2121; Email: l.j.howard@ljmu.ac.uk

Study Locations

• United Kingdom
  • Merseyside
    • Liverpool, Merseyside, United Kingdom, L3 3AF
      • Recruiting
      • Liverpool John Moores University
      • Contact: Luca J Howard; Phone Number: +44 151 231 2121; Email: l.j.howard@ljmu.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1- Biofeedback intervention + standard care; 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; 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.
No Intervention: Group 2: Standard care; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	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.	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: 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.	Through study recruitment and all data collection, an average of 2 years.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	During each 3-week usability testing period.
Phase 1: Receive feedback on the usability and acceptability of the biofeedback intervention	3) Researcher observations	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).	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).	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.	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.	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: 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.	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.	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.	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.	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.	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.	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.	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.	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	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.	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.	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.	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.	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.	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.	7-days pre and 7-days post intervention. (*Intervention group only*: Polar Pacer HRV additionally measured throughout 6-month intervention).

Collaborators and Investigators

• Sponsor: Liverpool John Moores University
• Collaborators: Liverpool Heart and Chest Hospital NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start (Actual): April 15, 2026
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): February 1, 2028

Study Registration Dates

• First Submitted: January 28, 2026
• First Submitted That Met QC Criteria: March 3, 2026
• First Posted (Actual): March 6, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 20, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Atrial fibrillation; Physical activity; mHealth; Nudge theory; Behavioural economics; Wrist worn technology
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Behavior; Atrial Fibrillation; Motor Activity
• Other Study ID Numbers: 25LJMUSPONSOR007; 360293 (Other Identifier: IRAS)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No