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

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.

Study Overview

• Status: Completed
• Conditions: Atrial Fibrillation
• Intervention / Treatment: Device: Apple Watch

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.

• Study Type: Interventional
• Enrollment (Actual): 436
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • North Holland
    • Amsterdam, North Holland, Netherlands
      • Cardiology Center of the Netherlands
    • Haarlem, North Holland, Netherlands, 2035 RC
      • Spaarne Gasthuis

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 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)

Exclusion Criteria:

• 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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Interventional group (Apple watch); These 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.	Device: Apple Watch; Smartwatch for detecting atrial fibrillation using photoplethysmography (PPG); Other Names: Smartwatch
No Intervention: Control group; Patients 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 the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The time until atrial fibrillation is first detected (days)	The number of days between the date of inclusion and the date AF is detected	6 months
The number of patients for whom medication for AF is initiated at the end of the study (anticoagulation and antiarrhythmic drugs)		6 months
The number of patients that undergo major cardiovascular events during the study period		6 months
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	6 months
Number of emergency department visits	Emergency department visits that take place during the study period, for any reason	6 months

Collaborators and Investigators

• Sponsor: Amsterdam University Medical Centers (UMC), Location Academic Medical Center (AMC)

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2022
• Primary Completion (Actual): July 17, 2025
• Study Completion (Actual): July 17, 2025

Study Registration Dates

• First Submitted: December 16, 2022
• First Submitted That Met QC Criteria: January 13, 2023
• First Posted (Actual): January 17, 2023

Study Record Updates

• Last Update Posted (Estimated): September 16, 2025
• Last Update Submitted That Met QC Criteria: September 10, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Telemedicine; Atrial fibrillation; Randomized controlled trial; Screening; Photoplethysmography; Smartwatch; Remote monitoring; Electrocardiography; Cardiac arrhythmia; Digital health; Wearable technology; Outpatient care
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation; Arrhythmias, Cardiac
• Other Study ID Numbers: 2021_209

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: Yes
• product manufactured in and exported from the U.S.: Yes