KardiaBand More Accurate Than Apple Watch 4 for Diagnosing AF

This study aimed to assess the diagnostic utility of the Apple Watch Series 4 (AW4) and KardiaBand (KB) in an elderly outpatient population.

Smartwatches and wearable technology capable of heart rhythm assessment have increased in use in the general population. The AW4 and KB are devices capable of obtaining single-lead electrocardiographic recordings, presenting a novel opportunity to detect paroxysmal arrhythmias. Consecutive recordings were taken from patients attending cardiology outpatient clinics from the AW4 and KB concurrently with 12-lead electrocardiography. Automated diagnoses and blinded single-lead electrocardiographic tracing interpretations by 2 cardiologists were analyzed. Analysis was also conducted to assess the effect of combined device and clinician interpretation.

The results of the study are:

• One hundred twenty-five patients were prospectively recruited (mean age 76 ± 7 years, 62% men).
• The accuracy of the automated rhythm assessment was higher with the KB than with the AW4 (74% vs 65%).
• For the detection of atrial fibrillation, the sensitivity and negative predictive value of the KB was 89% and 97%, respectively, and of the AW4 were 19% and 82%, respectively.
• Using hybrid automated and clinician interpretation, the overall accuracy of the KB and AW4 was 91% and 87%, respectively.

Thus, the KB automated algorithm outperformed the AW4 in its accuracy and sensitivity for detecting atrial fibrillation in the outpatient setting. Clinician assessment of the single-lead electrocardiogram improved accuracy. These findings suggest that although these devices' tracings are of sufficient quality, automated diagnosis alone is not sufficient for making clinical decisions about atrial fibrillation diagnosis and management.

Reference:

Comparison of 2 Smart Watch Algorithms for Detection of Atrial Fibrillation and the Benefit of Clinician Interpretation: SMART WARS Study by Christopher Ford, et al. published in the JACC: Clinical Electrophysiology.

https://www.jacc.org/doi/abs/10.1016/j.jacep.2022.02.013