WHOOP Abnormal Rhythm Notification

Study Overview
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Brief Summary
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The purpose of this protocol is to assess the sensitivity and specificity of a photoplethysmography (PPG)-based algorithm for the detection of atrial fibrillation as compared to a gold-standard assessment (wearable ECG patch) among a population of individuals with known atrial fibrillation and without known atrial fibrillation over a 7-day study period.

Detailed Description
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Atrial fibrillation (Afib) is the most common cardiac arrhythmia in the United States, affecting up to one in four individuals across the lifespan, and is associated with substantial morbidity and mortality. Fifteen percent of strokes in the United States are attributable to Afib, and nearly 20% of these occur in individuals with no prior Afib history. Because Afib is often paroxysmal, one-time screening is unlikely to capture those at risk. Thus, there has been an increasing interest in leveraging monitoring for Afib via wearable devices, which provide a novel method to detect Afib and determine the burden of Afib in the general population. Devices such as the WHOOP 4.0 strap use advanced sensors to detect pulse rate and other physiologic metrics in real-time. Given the high degree of pulse-rate variability in Afib, it is clear that algorithms evaluating data from these devices may be able to detect asymptomatic Afib. However, the sensitivity and specificity of the algorithm operating on data from the WHOOP 4.0 strap have not been formally evaluated in a clinical setting. The WHOOP strap measures changes in blood flow via photoplethysmography (PPG), from which timing between successive heartbeats (beat-to-beat intervals) is measured. While normal sinus rhythm tends to display beat-to-beat intervals of similar magnitude, those of cardiac arrythmias are characterized by higher variability and may follow particular patterns. The primary objective of this study is to assess the sensitivity and specificity of the WHOOP Strap ANF 1.0 classification algorithm for the detection of Afib as compared to a gold-standard assessment (one-week ECG patch monitoring using the BioTel ePatch).

Official Title
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Validation of a Photoplethysmography-Based Algorithm for Detection of Atrial Fibrillation Via a Wearable Device - WHOOP Abnormal Rhythm Notification

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Device: WHOOP 4.0 Strap
* Device: BioTel ePatch


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >= 22 years Known diagnosis of atrial fibrillation OR no history of arrhythmia as documented in the patient medical record Seen in a Yale New Haven Hospital-associated Primary Care or Cardiology Clinic Cell phone (IOS 15.0 or greater or Android 10 or greater) with an active data plan and willing to install the WHOOP Mobile Application software Full-time US resident Able to read, understand, and provide written informed consent in English Willing and able to participate in the study procedures as described in the consent form Able to communicate effectively with and follow instructions from the study staff Exclusion Criteria: Pre-existing WHOOP user with active account Has implantable cardiac device (e.g., pacemaker, ICD, LVAD) Solid organ transplant Sensitivity or allergy to ECG patch or skin glue Unwilling to wear WHOOP 4.0 strap for one week Unwilling to wear BioTel (ECG patch) ePatch for one week WHOOP strap should be the only wearable on the arm. Individuals unwilling to adhere to the proper usage of the WHOOP strap will be excluded. Unwilling to install the WHOOP Mobile Application software Unable to provide informed consent Non-English speaking (as the WHOOP Mobile Application software is English only) Known sensitivity to medical adhesives, isopropyl alcohol, watch bands, or electrocardiogram (ECG) electrodes including known allergy or sensitivity to polyamide, polyester, or elastane bands primarily used in wrist worn fitness devices Symptomatic (or active) allergic skin reactions Significant tremor that prevents the subject from being able to hold still. Acute myocardial infarction (MI) within 90 days of screening or other cardiovascular disease that, in the opinion of the investigator, increases the risk to the subject or renders data uninterpretable. Pregnant women: Women who report being pregnant at the time of study participation. Subjects taking rhythm control drugs including amiodarone, dronedarone, dofetilide, sotalol, flecainide, ibutilide, lidocaine, procainamide, propafenone, quinidine, tocainide.

Ages Eligible for Study
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Minimum Age: 22 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Atrial Fibrillation<br>Subjects with known diagnosis of atrial fibrillation (persistent or paroxysmal) documented in the medical record. | Device: WHOOP 4.0 Strap<br>* Subjects will receive both the WHOOP 4.0 Strap and the BioTel ePatch and will continuously wear each for one week. Data will be collected and analyzed by the study team upon return of the both devices from the subject.<br>Device: BioTel ePatch<br>* Subjects will receive both the WHOOP 4.0 Strap and the BioTel ePatch and will continuously wear each for one week. Data will be collected and analyzed by the study team upon return of the both devices from the subject.<br>|
| No atrial fibrillation<br>Subjects with no known diagnosis of atrial fibrillation as documented in the medical record. | Device: WHOOP 4.0 Strap<br>* Subjects will receive both the WHOOP 4.0 Strap and the BioTel ePatch and will continuously wear each for one week. Data will be collected and analyzed by the study team upon return of the both devices from the subject.<br>Device: BioTel ePatch<br>* Subjects will receive both the WHOOP 4.0 Strap and the BioTel ePatch and will continuously wear each for one week. Data will be collected and analyzed by the study team upon return of the both devices from the subject.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity of the PPG-based WHOOP ANF algorithm for detection of atrial fibrillation | Sensitivity is defined as the True Positives/(True Positives + False Negatives). A true atrial fibrillation reading will have an ECG patch reading consistent with sustained atrial fibrillation for at least 5 continuous minutes. A WHOOP ANF diagnosis of atrial fibrillation is defined as atrial fibrillations being detected using the internal algorithm. A true positive is defined as the count of individuals who have at least 1 window labelled as Afib by WHOOP ANF and which has 5+ minutes of continuous Afib as determined by the BioTel recording and confirmed by tachogram adjudication. A false negative is defined as individuals who do not have any windows labelled by WHOOP-ANF as having Afib but at least one window has 5+ minutes of continuous Afib as determined by the BioTel recording. | 7 days of continuous wear of the WHOOP 4.0 Strap and BioTel ePatch immediately post enrollment | 
| Specificity of the PPG-based WHOOP ANF algorithm for detection of atrial fibrillation | Specificity is defined as the True Negatives/(True Negatives + False Positives). A true atrial fibrillation reading will have an ECG patch reading consistent with sustained atrial fibrillation for at least 5 continuous minutes. A WHOOP ANF diagnosis of atrial fibrillation is defined as atrial fibrillations being detected using the internal algorithm. A true negative is defined as the count of individuals who do not have any windows labelled by WHOOP ANF as having Afib and none of these windows contain 5+ minutes of continuous Afib as determined by the BioTel recording. A false positive is defined as individuals who have windows labelled as Afib by WHOOP ANF but none of these windows contain 5 minutes or greater of continuous Afib as determined by BioTel recording or have 5+ minutes of continuous Afib as determined by BioTel recording but none can be verified by tachogram adjudication. | 7 days of continuous wear of the WHOOP 4.0 Strap and BioTel ePatch immediately post enrollment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concordance between WHOOP ANF and BioTel ePatch via epoch assessment | Comparison of each epoch by both WHOOP ANF and the BioTel ePatch for concordance using the following definitions: True Positive: An epoch detected by WHOOP ANF as atrial fibrillation that has >=5 mins of AFib as detected by the ECG patch. True Negative: An epoch that is NOT labelled as atrial fibrillation by the WHOOP ANF and has < 5 mins of AFib as detected by the ECG patch. Specificity of the algorithm on the epoch level: True Negative/(True Negatives + False Positives). Sensitivity of the algorithm on the epoch level: True Positives / (True Positives + False Negatives). Positive predictive value of the algorithm on the epoch level: True Positives / (True Positives + False Positives). Negative predictive value of the algorithm on the epoch level: True Negatives / (True Negatives + False Negatives). | 7 days of continuous wear of the WHOOP 4.0 Strap and BioTel ePatch immediately post enrollment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Atrial fibrillation, Wearable device