Apple Watch for Atrial Fibrillation Detection

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Mayo Clinic

Disqualifiers: Atrial fibrillation, Dementia, End-stage kidney disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 6 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 2 years

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests whether the Apple Watch can detect atrial fibrillation (AF), a heart condition causing irregular beats, before diagnosis. Participants will either wear an Apple Watch to monitor heart rhythms with a special app or receive usual care without the watch. Suitable candidates have undergone an ECG at Mayo Clinic and show signs of high AF risk but lack a diagnosis. As an unphased trial, this study allows participants to contribute to innovative research that could lead to early AF detection.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that the Apple Watch is safe for long-term monitoring of atrial fibrillation?

Research has shown that the Apple Watch is safe and effective for detecting atrial fibrillation (AFib). Its electrocardiogram (ECG) feature accurately identifies AFib. For instance, the Apple Heart Study demonstrated the watch's ability to detect irregular heart rhythms associated with AFib.

Participants in these studies reported no major safety issues, indicating that the device is generally well-tolerated for heart monitoring. Since the Apple Watch is already widely used and approved by the FDA for its ECG functions, its safety for these purposes is well-established. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about using the Apple Watch for atrial fibrillation detection because it offers a non-invasive, easily accessible way to monitor heart rhythm continuously. Unlike traditional methods, which often require bulky equipment or intermittent testing, the Apple Watch can seamlessly integrate into daily life, providing real-time data and early detection of irregular heartbeats. This approach could potentially lead to earlier diagnosis and management of atrial fibrillation, improving patient outcomes without the need for frequent doctor visits or complex devices.

What evidence suggests that the Apple Watch is effective for atrial fibrillation detection?

Research shows that the Apple Watch, which participants in this trial may use, effectively detects atrial fibrillation (AFib), a common heart rhythm issue. Studies indicate it correctly identifies AFib 94% of the time, demonstrating high sensitivity. It also accurately rules out AFib in 97% of people without the condition, indicating high specificity. These findings suggest the Apple Watch is a reliable tool for early AFib detection, which can be important for managing and treating heart health. ^{1 2 6 7 8}

Who Is on the Research Team?

Xiaoxi Yao, PhD

Principal Investigator

Mayo Clinic

Are You a Good Fit for This Trial?

This trial is for individuals who've had a specific ECG at Mayo Clinic and are at high risk of undetected atrial fibrillation, based on an AI-ECG score. Men must have a CHA2DS2-VASc2 score of 2 or higher; women need a score of 3 or more. It's not for those already diagnosed with atrial fibrillation, dementia, end-stage kidney disease, history of brain bleeding, or those with certain heart devices.

Inclusion Criteria

You have a high score that suggests a high chance of having a heart condition called atrial fibrillation.

You had a specific heart test called a 12-lead ECG at Mayo Clinic that lasted for 10 seconds.

I am at a higher risk for stroke due to my heart condition.

Exclusion Criteria

I have been diagnosed with dementia.

Missing date of birth

I have had bleeding in my brain before.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants in the experimental group wear an Apple Watch and use the Mayo Clinic ECG Study App for data collection

2 years

Continuous monitoring

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 years

What Are the Treatments Tested in This Trial?

Interventions

• Apple Watch

Trial Overview

The REGAL study is testing if the Apple Watch can be used as a long-term monitoring tool to spot early signs of atrial fibrillation—a heart condition that causes irregular heartbeat—by comparing it against traditional detection methods.

How Is the Trial Designed?

Group I: Apple Watch Intervention Group Experimental Treatment 1 Intervention

Participants will be asked to wear an Apple Watch and use the Mayo Clinic ECG Study App to collect and share data with the study team.

Group II: Control Group Active Control 1 Intervention

Participants will receive usual care.

Apple Watch is already approved in United States, European Union, Canada, Japan, China, Switzerland for the following indications:

Approved in United States as Apple Watch for:

• General wellness monitoring
• Heart rate monitoring
• Sleep tracking

Approved in European Union as Apple Watch for:

• General wellness monitoring
• Heart rate monitoring
• Sleep tracking
• ECG monitoring

Approved in Canada as Apple Watch for:

• General wellness monitoring
• Heart rate monitoring
• Sleep tracking

Approved in Japan as Apple Watch for:

• General wellness monitoring
• Heart rate monitoring
• Sleep tracking

Approved in China as Apple Watch for:

• General wellness monitoring
• Heart rate monitoring
• Sleep tracking

Approved in Switzerland as Apple Watch for:

• General wellness monitoring
• Heart rate monitoring
• Sleep tracking

Who Is Running the Clinical Trial?

Mayo Clinic

Lead Sponsor

Trials

3,427

Recruited

3,221,000+

Published Research Related to This Trial

A survey of 95 physicians revealed that nearly all (99.5%) opted for diagnostic testing in response to Apple Watch alerts for atrial fibrillation in asymptomatic patients, indicating a strong inclination towards further evaluation of these alerts.

There was significant variation in management approaches among different specialties, highlighting the need for standardized clinical guidelines for handling smartwatch AF notifications, as treatment decisions varied widely between primary care, emergency medicine, and cardiology physicians.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Physician responses to apple watch-detected irregular rhythm alerts. Demkowicz, PC., Dhruva, SS., Spatz, ES., et al.[2023]

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC11780081/

Diagnostic Accuracy of Apple Watch Electrocardiogram for ...

Conclusions. The Apple Watch ECG carries high accuracy in detecting atrial fibrillation, providing a convenient diagnostic option for patients.

2.

jacc.org

jacc.org/doi/10.1016/j.jacadv.2025.102133

Accuracy of Smartwatches in the Detection of Atrial ...

Device performance varied, with the Apple Watch achieving 94% sensitivity (95% CI: 89%-96%; I2 = 71%) and 97% specificity (95% CI: 93%-99%; I2 = ...

3.

apple.com

apple.com/healthcare/docs/site/Apple_Watch_Arrhythmia_Detection.pdf

Using Apple Watch for Arrhythmia Detection

Apple Watch customers have access to two software as medical device features to detect heart arrhythmias such as atrial fibrillation (AFib): the Irregular ...

4.

clinicaltrials.gov

clinicaltrials.gov/study/NCT05686330?cond=Atrial%20Fibrillation&term=Apple%20Watch&rank=1

Detection and Quantification of Atrial Fibrillation in High- ...

This is a randomized controlled trial evaluating atrial fibrillation (AF) detection through smartwatch-based screening in high-risk patients using an Apple ...

5.

sciencedirect.com

sciencedirect.com/science/article/pii/S2666501825001205

Diagnostic performance of single-lead electrocardiograms ...

The CART Ring outperformed the Apple Watch for automated atrial fibrillation detection, with higher sensitivity (84.6% vs 69.1%) and significantly fewer ...

6.

nejm.org

nejm.org/doi/full/10.1056/NEJMoa1901183

Large-Scale Assessment of a Smartwatch to Identify Atrial ...

The goal of the Apple Heart Study was to evaluate the ability of an irregular pulse notification algorithm to identify atrial fibrillation with ...

7.

support.apple.com

support.apple.com/en-us/108375

Track your AFib History with Apple Watch

Learn how to set up AFib History to track how frequently your heart shows signs of AFib and log life factors that can impact your condition.

8.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10757793/

The Reliability of the Apple Watch's Electrocardiogram - PMC

Detection sensitivity for atrial fibrillation (AF) was recently shown to be greatly increased by using short, intermittent ECG recordings.