Accuracy of the Apple watch for detection of AF: A multicenter experience

Abstract

Introduction:The Apple watch (AW) irregular rhythm notification (IRN) feature uses photoplethysmography to identify prolonged episodes of irregular rhythm suggestive of atrial fibrillation (AF). IRN is FDA cleared for those with no previous history of AF, however, these devices are increasingly being used for AF management. The objective of the present study was to determine the accuracy of the IRN in subjects with a previous diagnosis of nonpermanent AF.Methods: Subjects with a history of nonpermanent AF and either an insertable cardiac monitor (ICM) or cardiac implanted electronic device (CIED) with <5% ventricular pacing were fitted with an AW Series 5 for 6 months. AF episodes were compared between the ICM/CIED and IRN. The primary endpoints were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the IRN by subject for AF ≥1 h. Secondary endpoints were sensitivity and PPV by AF episode ≥1 h. Analysis was limited to a maximum of 10 ICM/CIED episodes per subject and included only those AF episodes occurring during active AW use confirmed by activity data.Results: Thirty participants were enrolled. Mean age was 65.4 ± 12.2 years and 40% were female. There were 10 ICMs and 20 CIEDs. Eleven subjects had AF on ICM/ CIED while the AW was worn, of whom 8 were detected by IRN. There were no false positive IRN detections by subject ("by subject" 72% sensitivity, 100% specificity, 100% PPV, and 90% NPV). Five subjects had AF only when the AW was not worn. There were a total of 70 AF episodes on ICM/CIED, 35 of which occurred while the AW was being worn. Of these, 21 were detected by IRN with 1 false positive ("by episode" sensitivity = 60.0%, PPV = 95.5%). Conclusion:In a population with known AF, the AW IRN had a low rate of false positive detections and high specificity.

The Impact of Heart Rate Variability Monitoring on Preventing Severe Cardiovascular Events

“…Also, it is good to know that in this study, there were no false-positive data. This study supports the use of the Apple smartwatch in atrial fibrillation detection as a screening method, but it needs improvements with respect to sensitivity [24].…”

Detection of Arrhythmias Using Smartwatches—A Systematic Literature Review

“…Studies revealed that the Apple Watch, either standalone or supplemented with KardiaBand, demonstrated over 90% accuracy in AF detection [53,63,68,69]. Diagnostic sensitivity and specificity were also consistently around 90% [53,57,60,[62][63][64]68]. Moreover, the Apple Watch proved effective in accurately determining heart rate, even during tachyarrhythmias [51,52,56].…”

“…The study found no instances of false positive IRN detections, achieving a sensitivity of 72%, a specificity of 100%, a PPV (Positive predictive value.) of 100%, and a NPV (Negative predictive value) of 90% [64].…”

Sixty seconds on . . . Apple Watch

“…Atrial fibrillation causes shortness of breath and fatigue and can be a sign of increased risk of stroke. The Apple Watch basically works in the same way as a pulse oximeter3—shining a light and using the absorption of that light to work out changes in blood volume over that patch of skin. Pulse oximeters then work out and display blood oxygen volume, but the watch goes further to calculate heart rhythms and, crucially, how much time the person has spent with an abnormal heartbeat.…”