Rationale and design of a large-scale, app-based study to identify cardiac arrhythmias using a smartwatch: The Apple Heart Study

Abstract

Background Smartwatch and fitness band wearable consumer electronics can passively measure pulse rate from the wrist using photoplethysmography (PPG). Identification of pulse irregularity or variability from these data has the potential to identify atrial fibrillation or atrial flutter (AF, collectively). The rapidly expanding consumer base of these devices allows for detection of undiagnosed AF at scale. Methods The Apple Heart Study is a prospective, single arm pragmatic study that has enrolled 419,093 participants ( NCT03335800 ). The primary objective is to measure the proportion of participants with an irregular pulse detected by the Apple Watch (Apple Inc, Cupertino, CA) with AF on subsequent ambulatory ECG patch monitoring. The secondary objectives are to: 1) characterize the concordance of pulse irregularity notification episodes from the Apple Watch with simultaneously recorded ambulatory ECGs; 2) estimate the rate of initial contact with a health care provider within 3 months after notification of pulse irregularity. The study is conducted virtually, with screening, consent and data collection performed electronically from within an accompanying smartphone app. Study visits are performed by telehealth study physicians via video chat through the app, and ambulatory ECG patches are mailed to the participants. Conclusions The results of this trial will provide initial evidence for the ability of a smartwatch algorithm to identify pulse irregularity and variability which may reflect previously unknown AF. The Apple Heart Study will help provide a foundation for how wearable technology can inform the clinical approach to AF identification and screening. (Am Heart J 2019;207:66–75.)

Mobile health and cardiac rehabilitation in older adults

“…More recently, the increase in commercially available wearable devices (such as the Apple Watch [Apple, Cupertino, California]) has made arrhythmia detection possible by portable sensors. Wrist sensors, using photoplethysmographic monitoring (optically‐obtained measurements that detect changes in light related to blood flow in capillary beds, similar to those used for skin‐based pulse oximeters) can measure heart rate, heart rate variability, and use associated algorithms to detect arrhythmias including atrial fibrillation . Portable electrodes, such as the AliveCor Kardia Band (AliveCor, Mountain View, California), can also be connected to a wearable device and quickly generate a one‐lead electrocardiogram (ECG) to detect the presence of atrial fibrillation .…”

Novel wearable and contactless monitoring devices to identify deteriorating patients in the clinical setting: a systematic review protocol

“…A recent metaanalysis and systematic review of novel continuous noninvasive blood pressure monitoring based on tonometry and volume clamp methods showed larger than acceptable inaccuracy and imprecision compared to gold standard measurements over normal physiological ranges of blood pressure [37]. Finally, the recent Apple Watch study [38], while showing great promise for measurement of tachycardias, measures one single aberrant rhythm, and not in the critically unwell.…”

Secondary prevention of ischaemic stroke

“…If the software is approved by the Therapeutic Goods Administration for inclusion or registration on the Australian Register of Therapeutic Goods, patients will be able to record ECGs at leisure and receive alerts for possible AF, advising them to seek medical advice. The accuracy of the device and ability to drive clinical management was examined in the Apple Heart Study, a prospective, single arm pragmatic study that enrolled more than 400 000 Apple customers . Results were announced at the American College of Cardiology annual scientific meeting in March 2019 .…”

“…The accuracy of the device and ability to drive clinical management was examined in the Apple Heart Study, a prospective, single arm pragmatic study that enrolled more than 400 000 Apple customers. 20 Results were announced at the American College of Cardiology annual scientific meeting in March 2019. 21 Overall, the device was reasonably effective, with a positive predictive value of 71% of detecting AF on a single-dot ECG patch at the time of watch notification.…”