Early Observations of Population Characteristics for an Electrocardiogram-enabled Smartwatch in the United States.

Hannah Truong, BS ^1,2, Nandini Nayar, MS ¹, Aniket Zinzuwadia, BS ^1,3, Noor Osman, MPH ¹, Jana Goldberg, MD, FACC ¹, Mark Hanson, PhD ^1,4, Jeffrey Wessler, MD, Mphil, FACC ^{1,5 1} Heartbeat Health, New York, NY, ² Washington University School of Medicine in St. Louis, St. Louis, MO, ³ Harvard Medical School, Boston, MA, ⁴ The George Washington University Department of Emergency Medicine, Innovative Practice and TeleHealth, Washington, DC, ⁵ Northwell Health, Manhasset, NY

Background

Over one-in-five Americans now use a smartwatch or fitness tracker on a daily basis, and many of these consumer wearable technologies now offer electrocardiogram (ECG) capabilities. The wearable watch segment had over 25% year-over-year growth in 2021.

Expert interpretation of single-lead ECGs has demonstrated high diagnostic accuracy in atrial fibrillation (AF) detection, suggesting potential as a screening tool.

Generalizability concerns remain given limited available data on demographic data, such as age and geographic distributions of consumer smartwatch users.

Study Design

After obtaining FDA clearance, consumer smartwatch was launched in the United States in November 2021 and enabled users to transmit single-lead ECG recordings.

Between November 2021 and May 2022, Heartbeat Health, a team with trained virtual cardiology providers, received and interpreted ECG recordings from 13,915 smartwatch users.

Each reading was classified into five categories: 1) atrial fibrillation 2) normal sinus rhythm 3) high heart rate 4) low heart rate 5) possible other arrhythmia and 6) artifact. ECG findings were categorized by age and state Bloomberg Innovation Index (BII) for population analysis.

Principal Findings

Figure 1 Bloomberg Innovation Index Quintiles of US States

Figure 2 Bloomberg Innovation Index Metrics

Research & Development Manufacturing High-Tech Companies Postsecondary Education Research Personel Patent Activity Government Regulation

Annual private & public R&D spending Gross value added by specialized manufacturing Density & market capitalization of high-tech companies Percentage of population with a postsecondary degree (esp. STEM) Concentration of professionals working in R&D Number of patents and patent lawsuits (Not Quantified)

Chart 1 Smartwatch User Population Characterization

Graph1 Percent of Users by State Bloomberg Innovation Index Quintile

Graph 2 User AF Prevalence by State Bloomberg Innovation Index Quintile

Conclusions & Implications

A large-scale trained provider review of smartwatch-enabled ECGs revealed rates of AF that were lower than the widely understood prevalence of AF in the US, suggestive of a potential demographic gap between consumers with access versus those that are more likely to surface undiagnosed AF via smartwatch ECG screening.

Characterization of smartwatch ECG users revealed a higher share of users and younger users in states with higher BII, measured by density of technology companies, research & development, and postsecondary education.

Wearables such as smartwatches have demonstrated higher in-usage time than other technologies, such as tablets, but have still not gained the level of penetration seen in mobile phones. With the growing penetration of consumer smartwatches, equitable distribution of innovation is increasingly important.

Disclosures

The authors of this study were employed by Heartbeat Health ("Significant" or "Modest support") at the time of this study.

All clinical interpretation and data analysis for this study was done independent of the consumer smartwatch company. The authors have no other relevant disclosures for this study as presented.