Evaluation of a Wearable Heart Monitor Combined with an Irregular Heart Rhythm Notification Solution in a Large-Scale Healthy Population: A Prospective Observational Study (Preprint)

BACKGROUND Atrial fibrillation is a risk factor for stroke, systemic embolism, and mortality. Although electrocardiogram monitoring tools, such as Holter monitors, have been extensively used in clinical practice, they have several limitations. Thus, smartwatches have become an option for arrhythmia screening. OBJECTIVE To test whether a wearable monitor communicating with an irregular heart rhythm notification on a smartwatch would produce a significant number of false-positive notifications in healthy individuals in daily living. METHODS This observational study was divided into three phases. Phase 1: Participants went through standard electrocardiogram screening for arrhythmia. Those with regular sinus rhythm were provided with a smartwatch and smartphone. Phase 2: The smartwatch was worn for at least seven days in this, the remote phase. Phase 3: In case of an irregular heart rhythm notification during phase 2, participants were submitted to 24-hour Holter monitoring. RESULTS We recruited 2,446 participants in phase 1, of whom 153 were excluded for electrocardiogram alterations or other reasons. In phase 2, forty-four (1.9%) participants were discontinued due to too few follow-up days, wrist allergies, personal reasons, loss of collected data, and device issues. Of the participants who completed phases 1 and 2 (n=2,249), two participants (0.1%) received an irregular heart rhythm notification in phase 2. As these two participants were not diagnosed with atrial fibrillation during phase 1, they were classified as false positives. The specificity of the study was 99.9% (95% confidence interval of 99.7–100.0%), and the number of false positives was not statistically significant (p=.61). CONCLUSIONS The smartwatch generated few unnecessary irregular heart rhythm notifications during seven days of follow-up. The specificity of the device was 99.9%. Therefore, the irregular heart rhythm notification feature on the SAMSUNG smartwatch can be used in the general population without a significant number of false positives for atrial fibrillation.