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Atrial FibrillationEQUALNCT05686330

Detection and Quantification of Atrial Fibrillation in High-risk Patients Using a Smartwatch Wearable (Apple Watch)

A study testing Apple Watch in people with Atrial Fibrillation, run by Amsterdam University Medical Centers (UMC), Location Academic Medical Center (AMC) at 2 sites in Netherlands.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is a randomized controlled trial evaluating atrial fibrillation (AF) detection through smartwatch-based screening in high-risk patients using an Apple Watch with integrated PPG and ECG functions. Read more about this study

Who is it for?
Ages 65 years and older
Conditions the study is for
Atrial Fibrillation
What is being tested?
Apple Watch
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
436 participants
Where
2 sitesNetherlands
Study dates
16 Nov 2022to 17 Jul 2025
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 65 years and older
  • All sexes
  • No healthy volunteers
  • Older adult

Who may be able to join

  • Age ≥ 65 years
  • Chadsvasc score ≥2 for men and ≥ for women at the time of eligibility screening
  • Written informed consent as documented by signature from the participant
  • Possession of iPhone (6S or later)

Who cannot join

  • Diagnosis of atrial fibrillation or atrial flutter
  • Currently on anticoagulation therapy
  • Cardiac implanted electronic device (pacemaker, ICD)
  • Smartwatch cannot be worn due to comprehensible reasons (allergic reactions, wounds, amputations, other)
  • Significant mental or cognitive impairment

Trial locations and contacts

2 sites in 1 country.

Netherlands2 sites
  • Cardiology Center of the Netherlands

    Amsterdam, North Holland

  • Spaarne Gasthuis

    Haarlem, North Holland, 2035 RC

Other trials in Netherlands

About this study

Official title: Enhanced Detection and Quickened Diagnosis of Atrial Fibrillation Using the Apple Watch: A Randomised Controlled Trial (EQUAL Study)

This is a randomized controlled trial evaluating atrial fibrillation (AF) detection through smartwatch-based screening in high-risk patients using an Apple Watch with integrated PPG and ECG functions.

Read the detailed description

This is a multicenter randomized controlled trial evaluating whether six months of heart rate and rhythm monitoring with a smartwatch (Apple Watch Series 5 or 8) equipped with photoplethysmography (PPG) and ECG functions increases atrial fibrillation (AF) detection in high-risk cardiac patients (age ≥65, CHA₂DS₂-VASc ≥2 for men, ≥3 for women) without previously known AF.

Patients are randomized to either smartwatch-based monitoring or standard care. Participants in the intervention group receive an Apple Watch paired with a smartphone app and are instructed to wear the device for at least 12 hours per day. Continuous rhythm monitoring is performed using PPG, with ECGs recorded upon symptom onset or irregular rhythm detection. ECG data are transmitted via the app to a secure platform and reviewed within 24 hours by an independent eHealth team supervised by a cardiologist. Patients and their treating physicians are notified upon new AF diagnoses.

To evaluate the primary endpoint, a total of 218 patients per arm were required according to the sample size calculation.

Being tested
Apple Watch
Keywords
Atrial fibrillation, Cardiac arrhythmia, Smartwatch, Wearable technology, Digital health, Photoplethysmography, Electrocardiography, Remote monitoring, Screening, Randomized controlled trial, Outpatient care, Telemedicine
Medical subject headings
Atrial Fibrillation, Arrhythmias, Cardiac

What participants receive

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

  • Apple WatchDevice

    Also called Smartwatch

    Smartwatch for detecting atrial fibrillation using photoplethysmography (PPG)

Study groups in NCT05686330
Study groupRoleWhat they receive
Interventional group (Apple watch)ExperimentalThese participants will wear a smartwatch (Apple Watch) for 6 months during 12 hours a day. The smartwatch will alarm the participant if an irregular heart rhythm is detected. When a participant experiences any symptoms or receives an irregular heartbeat notification, they can record an ECG with the smartwatch. The ECG will automatically be sent to the Telecure team for evaluation.
Receives: Device: Apple Watch
Control groupNo interventionPatients in the control group received standard care, which could include conventional rhythm monitoring methods such as Holter monitoring, in-hospital telemetry, or the use of handheld mobile ECG devices, at the discretion of the treating cardiologist. At the end of the study period the investigator will either call the participant to check for these outcome measures.

What is being measured

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

  1. The incidence of atrial fibrillation

    Detected with an Apple watch or with any other device such as a holter or on an ECG or telemetry

    Measured: 6 months

Secondary outcomes (5)
  1. The time until atrial fibrillation is first detected (days)

    The number of days between the date of inclusion and the date AF is detected

    Measured: 6 months

  2. The number of patients for whom medication for AF is initiated at the end of the study (anticoagulation and antiarrhythmic drugs)

    Measured: 6 months

  3. The number of patients that undergo major cardiovascular events during the study period

    Measured: 6 months

  4. Number of emergency department visits

    Emergency department visits that take place during the study period, for any reason

    Measured: 6 months

  5. The number of new arrhythmia diagnoses other than AF in each study arm

    Detected by either the Apple watch, telemetry, holter or other devices used to detect arrhythmias

    Measured: 6 months

Timeline

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

  1. First posted17 Jan 2023
  2. Study start16 Nov 2022
  3. Primary completion17 Jul 2025
  4. Study completion17 Jul 2025

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
Diagnosis
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
436 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05686330
Sponsor's protocol ID
2021_209
Acronym
EQUAL
Status last verified
Sep 2025
First submitted
16 Dec 2022
Last updated
16 Sep 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
Undecided

Publications

  • van Steijn NJ, Blommestijn IS, Blok S, Pepplinkhuizen S, Somsen GA, Knops RE, Breukel L, Tijssen JGP, Tulevski II, Croon PM, Winter MM. Enhanced Detection and Prompt Diagnosis of Atrial Fibrillation Using Apple Watch: A Randomized Controlled Trial. J Am Coll Cardiol. 2026 Apr 14;87(14):1714-1728. doi: 10.1016/j.jacc.2025.11.032. Epub 2026 Jan 22.

    PubMed 41569211

Questions about this trial

What is this clinical trial studying?

A study testing Apple Watch in people with Atrial Fibrillation, run by Amsterdam University Medical Centers (UMC), Location Academic Medical Center (AMC) at 2 sites in Netherlands.

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 4 inclusion and 5 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: finished, as of the sponsor's last update on 16 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Netherlands. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

The incidence of atrial fibrillation (time frame: 6 months). 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 NCT05686330, which also lists 1 linked publication.

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 16 Sep 2025.

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