Physician responses to apple watch-detected irregular rhythm alerts

Abstract

Background: While the US Food and Drug Administration (FDA) has cleared smartwatch software for detecting atrial fibrillation (AF), there is lack of guidance on management by physicians. We sought to evaluate the approach to management of Apple Watch alerts for AF by physicians and assess whether respondent and case characteristics were associated with their approach.

Methods: We conducted a case-based survey of physicians practicing primary care, emergency medicine, and cardiology at 2 large academic centers (Yale and University of California San Francisco) between September and December 2021. Cases described asymptomatic patients receiving Apple Watch AF alerts; cases varied in sex, race, medical history, and notification frequency. We evaluated physician responses among prespecified diagnostic testing, referral, and treatment options.

Results: We emailed 636 physicians, of whom 95 (14.9%) completed the survey, including 39 primary care, 25 emergency medicine, and 31 cardiology physicians. Among a total of 192 cases (16 unique scenarios), physicians selected at least one diagnostic test in 191 (99.5%) cases and medications in 48 (25.0%). Physicians in primary care, emergency medicine, and cardiology reported varying preference for patient referral (14%, 30%, and 16%, respectively; P=.048), rhythm monitoring (84%, 46%, and 94%, respectively; P<.001), measurement of BNP (8%, 20%, and 2%; P=.003), and use of antiarrhythmics (16%, 4%, and 23%; P=.023). There were few physician differences in reported practices across patient demographics (sex and race), clinical complexity, and alert frequency of the clinical case.

Conclusions: In hypothetical cases of patients presenting without clinical symptoms, physicians opted for further diagnostic testing and often to medical intervention based on Apple Watch irregular rhythm notifications. There was also considerable variation across physician specialties, suggesting a need for uniform clinical practice guidelines. Additional study is required before irregular rhythm notifications should be used in clinical settings.

Figure 1.. Testing and interventions ordered overall.

Among 95 participants, 192 hypothetical cases were completed. Here we report the average proportion of cases in which respondents indicated that they were “extremely likely” or “somewhat likely” to order specific diagnostic tests, referral/consultation, and therapeutic interventions. “Rhythm monitoring” indicates that any of the following were selected: event monitor, implantable loop recorder, patch monitor, or a commercially available heart rhythm monitor such as AliveCor. “Antiarrhythmics” included selection of a beta blocker or calcium channel blocker, or a class IC or III antiarrhythmic. ECG = electrocardiogram, TTE = transthoracic echocardiogram, and BNP = brain natriuretic peptide. Selections for referral, stress test, and aspirin were missing in 1 (0.5%) case.

Figure 2.. Frequency of (A) diagnostic testing and (B) medication treatment across cases.

The number of diagnostic tests (among ECG, rhythm monitoring, TTE, stress test, and BNP) and types of medications (among aspirin, antiarrhythmics, and anticoagulation) were tallied in each case (N = 192). The distributions of frequencies are reported here.