AzTrials
AzTrials

Atrial FibrillationNEXAFNCT04991337

Effects of Detraining in Endurance Athletes With Atrial Fibrillation

A study testing Detraining group in people with Atrial Fibrillation, run by Vestre Viken Hospital Trust at 1 site in Norway.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
Search all trials

Trial summary

Atrial fibrillation (AF) affects more than 43 million people worldwide, but specific exercise recommendations do not exist for this group of patients. Despite a lack of evidence, athletes are often advised to reduce exercise intensity (detraining) after being diagnosed with AF. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Atrial Fibrillation
What is being tested?
Detraining group
Could I receive a placebo?
No, everyone receives an active treatment
How many people
120 participants
Where
1 siteNorway
Study dates
5 Jan 2022to 1 Jan 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Signed informed consent
  • Age ≥ 18 years
  • Diagnosed with paroxysmal atrial fibrillation (verified by electrocardiogram)
  • Report >5 (running, rowing) or >8 (cycling, cross-country skiing), weekly hours, respectively, of endurance sport
  • At least two anamnestic (self-reported) episodes of atrial fibrillation, of which one during the last six months
  • Use a smartphone and agree to connect their sportswatch with a web-based platform for monitoring of exercise

Who cannot join

  • Permanent atrial fibrillation
  • Cardiac conditions (including valvular heart disease of moderate or greater severity, symptomatic ischemic heart disease)
  • Left ventricular ejection fraction <45%
  • Hypertension (>140/90)
  • Diabetes mellitus
  • Hyperthyroidism
Show all 15Show fewer
  • Smoking during the last 5 years
  • Alcohol intake >20 alcohol units/week
  • Use of illegal or performance enhancing drugs
  • Body mass index >30kg/m2
  • Injuries preventing physical exercise
  • Pregnancy
  • Participation in conflicting intervention research studies
  • Planned atrial fibrillation ablation within the next six months
  • The individual refuses to have an insertable cardiac monitor, blood samples taken or be part of the detraining group

Trial locations and contacts

1 site in 1 country.

Marius Myrstad, MD;PhD contact

+47 92255945

marium@vestreviken.no

Marius Myrstad, MD, PhD contact

+47 92255945

marium@vestreviken.no

Norway1 site, 1 recruiting

  • Vestre Viken Health Trust, Baerum Hospital

    Bærums verk

    Marius Myrstad, MD, PhD

    Recruiting

Other trials in Norway

About this study

Official title: Effects of Detraining in Endurance Athletes With Atrial Fibrillation (NEXAF Detraining)

Atrial fibrillation (AF) affects more than 43 million people worldwide, but specific exercise recommendations do not exist for this group of patients. Despite a lack of evidence, athletes are often advised to reduce exercise intensity (detraining) after being diagnosed with AF. This randomized controlled trial will be the first study that investigates effects of detraining in endurance athletes. Participants will be randomized to an intervention group that will be instructed to refrain from high intensity exercise, and a control group. The study aims to clarify whether detraining might reduce the burden of AF and has the potential to guide development of exercise guidelines for AF patients.

Read the detailed description

Atrial fibrillation (AF) affects more than 43 million people worldwide, but specific exercise recommendations do not exist for this group of patients. Despite a lack of evidence, athletes are often advised to reduce exercise intensity (detraining) after being diagnosed with AF. This randomized controlled trial will be the first study that investigates effects of detraining in endurance athletes. Participants will be included at Bærum Hospital, St.Olavs Hospital, Trondheim, Baker Institute, Melbourne, Leuven University Hospital, Antwerp University Hospital, AZ Jan Palfijn Gent and Jessa Hospital Hasselt, Belgium. In total 120 participants will be monitored with a chest-strap heart rate (HR) monitor and sportswatch (exercise intensity), and an Insertable Cardiac Monitor (ICM, AF burden). Participants will be randomized to an intervention group (n=60) that will be instructed to refrain from high intensity exercise (H) >75% of maximal HR (HRmax)) for a period of 16 Weeks, or a control group (n=60) that will be instructed to perform at least three weekly sessions of high intensity training (HR ≥85% of HRmax. The primary endpoint will be AF burden, as measured by continuous monitoring with ICMs and calculated as the cumulative duration of all AF episodes lasting ≥30sec divided by total duration of monitoring. The study aims to clarify whether detraining might reduce the burden of AF and has the potential to guide development of exercise guidelines for AF patients. The investigators will also study exercise-induced cardiac remodeling, aiming to improve the understanding of underlying pathophysiological mechanisms for AF.

Being tested
Detraining group, Control group
Keywords
heart
Medical subject headings
Atrial Fibrillation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Detraining groupBehavioural

    Detraining is defined as exercise corresponding to a heart rate ≤75% of maximum heart rate and ≤80% of the self-reported average weekly amount of exercise (hours/week) during the past six months, for a period of 16 weeks.

  • Control groupBehavioural

    At least three weekly sessions of high intensity exercise, corresponding to a heart rate ≥85% of maximum heart rate, and otherwise continue endurance exercise as usual.

Study groups in NCT04991337
Study groupRoleWhat they receive
Detraining groupExperimentalWill be instructed to avoid high-intensity exercise corresponding to a heart rate >75% of maximum heart rate, and a total duration of exercise (hours/week) corresponding to >80% of the self-reported average weekly amount of exercise (hours/week) during the past six months, for a period of 16 week.
Receives: Behavioral: Detraining group
Control groupExperimentalWill be instructed to perform at least three weekly sessions of high intensity exercise, corresponding to a HR ≥85% of maximum heart rate, and otherwise continue endurance exercise as usual.
Receives: Behavioral: Control group

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Atrial fibrillation burden

    Atrial fibrillation burden (time with atrial fibrillation) as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring and reported as percentages.

    Measured: Measured during the last 4 weeks (week 13-16) of the 16-week intervention period

Secondary outcomes (38)

  1. Atrial fibrillation burden

    Atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring.

    Measured: Measured during the first 4 weeks (week 1-4) of the 16-week intervention period

  2. Atrial fibrillation burden

    Atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring.

    Measured: Measured during week 5-8 of the 16-week intervention period

  3. Atrial fibrillation burden

    Atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring.

    Measured: Measured during week 9-12 of the 16-week intervention period

  4. Cumulative atrial fibrillation burden

    Atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring.

    Measured: Measured during the entire 16-week intervention period

  5. Atrial fibrillation episode duration

    Mean duration of atrial fibrillation episodes lasting ≥30sec

    Measured: Measured during the 16-week intervention period

  6. Atrial fibrillation episodes

    Number of atrial fibrillation episodes lasting ≥30sec, as measured by insertable cardiac monitor

    Measured: Measured during the first 4 weeks (week 1-4) of the 16-week intervention period

  7. Atrial fibrillation episodes

    Number of atrial fibrillation episodes lasting ≥30sec, as measured by insertable cardiac monitor

    Measured: Measured during week 5-8 of the 16-week intervention period

  8. Atrial fibrillation episodes

    Number of atrial fibrillation episodes lasting ≥30sec, as measured by insertable cardiac monitor

    Measured: Measured during week 9-12 of the 16-week intervention period

  9. Atrial fibrillation episodes

    Number of atrial fibrillation episodes lasting ≥30sec, as measured by insertable cardiac monitor

    Measured: Measured during the last 4 weeks (week 13-16) of the 16-week intervention period

  10. Cumulative atrial fibrillation episodes

    Number of atrial fibrillation episodes lasting ≥30sec, as measured by insertable cardiac monitor

    Measured: Measured during the 16-week intervention period

  11. Days with atrial fibrillation

    Days with at least one episode of atrial fibrillation lasting ≥30sec

    Measured: Measured during the 16-week intervention period

  12. Days without atrial fibrillation

    Days without atrial fibrillation episodes

    Measured: Measured during the 16-week intervention period

  13. Relative change in atrial fibrillation burden

    Relative change in atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring

    Measured: Measured during the 4-week baseline period prior to randomization and during the last 4 weeks of the 16-week intervention period

  14. Relative change in atrial fibrillation burden

    Relative change in atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring

    Measured: Measured during the 4-week baseline period prior to randomization and during the first 4 weeks of the 16-week intervention period

  15. Relative change in atrial fibrillation burden

    Relative change in atrial fibrillation burden as measured by continuous monitoring with insertable cardiac monitor and calculated as the cumulative duration of all atrial fibrillation episodes lasting ≥30sec divided by total duration of monitoring

    Measured: Measured during the 4-week baseline period prior to randomization and during the entire 16-week intervention period

  16. Adherence to prescribed exercise

    Adherence to prescribed exercise (>80% of exercise with ≥85% and ≤75% of maximum heart rate, respectively)

    Measured: 16 weeks

  17. Exercise capacity

    Peak oxygen uptake (VO2peak)

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  18. Atrial volumes

    Right and left atrial volumes measured with echocardiography

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  19. Ventricular volumes

    Right and left ventricular volumes measured with echocardiography

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  20. Atrial function

    Left atrial function measured by strain with echocardiography

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  21. Ventricular function

    Right and left ventricular function measured by strain with echocardiography

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  22. Systolic function

    Left ventricular ejection fraction measured by strain with echocardiography

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  23. Atrial fibrillation symptoms

    Self-reported number of symptomatic atrial fibrillation episodes

    Measured: Measured by questtionnaire at the baseline study visit and at the final study visit after the 16-week intervention period

  24. Atrial Fibrillation Effect on QualiTy-of-life questionnaire

    Measured with the Atrial Fibrillation Effect on QualiTy-of-life questionnaire (AFEQT).

    Minimum score 0, maximum score 100, higher values indicate better quality of life

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  25. Atrial fibrillation hospitalizations

    Number of unplanned hospitalizations due to atrial fibrillation cardioversion or ablation

    Measured: Throughout study completion, an average of 22 weeks

  26. Modified European Heart Rhythm Association Symptom Scale (mEHRA) symptom classification

    Modified European Heart Rhythm Association Symptom Scale (mEHRA) questionnaire. The scale ranges from minimum 1 to maxiumum 4, a higher score indicates a worse symptom burden

    Measured: Measured at the baseline study visit and at the final study visit after the 16-week intervention period

  27. Number of ventricular arrhythmias

    Ventricular arrhythmias lasting ≥12 ventricular complexes as measured by continuous monitoring with insertable cardiac monitor

    Measured: Throughout study completion, an average of 22 weeks

  28. Number of adverse events

    Any unfavorable and unintended sign, symptom or illness that develops or worsens during the trial period will be reported as adverse events (AE). A serious adverse event (SAE) is defined as death, any life-threatening event or any inpatient hospitalisation

    Measured: Throughout study completion, an average of 22 weeks

  29. Cardiovascular risk factors measured by blood pressure

    Measure of blood pressure (mmHg)

    Measured: Measured at baseline and after the 16-week intervention period

  30. Cardiovascular risk factors measured by blood lipids

    Blood lipids (mmol/L)

    Measured: Measured at baseline and after the 16-week intervention period

  31. Cardiovascular risk factors measured by weight

    Weight (kg)

    Measured: Measured at baseline and after the 16-week intervention period

  32. Cardiovascular risk factors measured by BMI

    BMI (weight and height will be combined to report BMI in kg/m^2)

    Measured: Measured at baseline and after the 16-week intervention period

  33. Cardiovascular risk factors measured by smoking

    Smoking (pack years)

    Measured: Measured at baseline and after the 16-week intervention period

  34. Cardiovascular risk factors measured by alcohol units

    Alcohol use (units)

    Measured: Measured at baseline and after the 16-week intervention period

  35. Cardiovascular biomarkers - inflammation markers

    Markers for inflammation markers; interleukines and hrCRP (mg/L)

    Measured: Measured at baseline and after the 16-week intervention period

  36. Cardiovascular biomarkers - markers for myocardial damage

    Markers for myocardial damage, measured by troponin T (ng/L) and NT-ProBNP (ng/L)

    Measured: Measured at baseline and after the 16-week intervention period

  37. Immediate effects on arrhythmia burden of high-intensity exercise

    Ahrrythmias measured with 24-hour electrocardiogram after peak exercise testing

    Measured: 24 hours after after peak exercise testing

  38. Immediate effects on biomarkers of exercise

    Blood sampling at peak exercise for analyses of cardiac Troponins, NT-pro-BNP, interleukins, C-reactive protein

    Measured: At peak exercise during cardiopulmonary exercise testing

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Aug 2021
  2. Study start5 Jan 2022
  3. Primary completion1 Jan 2024 (estimated)
  4. Study completion1 Jan 2024 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Two-arm international multicenter open-label randomized (1:1) controlled trial with blinded end-point evaluation.
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
120 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04991337
Sponsor's protocol ID
NEXAF Detraining
Acronym
NEXAF
Status last verified
Dec 2022
First submitted
7 May 2021
Last updated
23 Dec 2022
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Apelland T, Letnes JM, Janssens K, Claessen G, Tveit A, Sellevold AB, Mitchell A, Willems R, Onarheim S, Enger S, Kizilkilic SE, Miljoen H, Elliott A, Loennechen JP, La Gerche A, Myrstad M; NEXAF Investigators. Arrhythmia burden, symptoms and quality of life in female and male endurance athletes with paroxysmal atrial fibrillation: a multicentre cohort study in Norway, Australia and Belgium. BMJ Open. 2025 Aug 5;15(8):e100496. doi: 10.1136/bmjopen-2025-100496.

    PubMed 40764068

  • Apelland T, Sellevold AB, Letnes JM, Onarheim S, Enger S, Tveit A, Delpire B, Claessen G, La Gerche A, Loennechen JP, Berge T, Myrstad M; NEXAF Investigators; NEXAF investigators. Cardiac arrhythmia assessment with patch electrocardiogram versus insertable cardiac monitor: a cohort study in endurance athletes with atrial fibrillation. BMJ Open. 2025 Jan 6;15(1):e093250. doi: 10.1136/bmjopen-2024-093250.

    PubMed 39762092

  • Apelland T, Janssens K, Loennechen JP, Claessen G, Sorensen E, Mitchell A, Sellevold AB, Enger S, Onarheim S, Letnes JM, Miljoen H, Tveit A, La Gerche A, Myrstad M; NEXAF investigators. Effects of training adaption in endurance athletes with atrial fibrillation: protocol for a multicentre randomised controlled trial. BMJ Open Sport Exerc Med. 2023 Apr 11;9(2):e001541. doi: 10.1136/bmjsem-2023-001541. eCollection 2023.

    PubMed 37073174

Questions about this trial

What is this clinical trial studying?

A study testing Detraining group in people with Atrial Fibrillation, run by Vestre Viken Hospital Trust at 1 site in Norway.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 23 Dec 2022. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

Contact Marius Myrstad, MD;PhD (+47 92255945, marium@vestreviken.no), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Atrial fibrillation burden (time frame: Measured during the last 4 weeks (week 13-16) of the 16-week intervention period). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04991337, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Dec 2022.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in