Majmudar, Maulik D.

Introduction: Repeated 6MWT in clinic are inconvenient for patients and disruptive to usual clinic throughput. Digital measures may be a means to overcome these challenges and reliably measure functional capacity. Methods: As part of an observational clinical trial (NCT04191356), during an 8-week observation period, patients with heart failure (HF) utilize arm-band biosensors (Biofourmis Everion®) for at least 15 hours daily while carrying out daily activities and complete an in-clinic investigator-guided 6MWT on the first and last days of participation. Interim data (N=30, age 56.17 ± 11.26; 24 males; 3 NYHA I, 25 NYHA II, 2 NYHA III) are used for validation, where the distance of baseline 6MWT is used as reference standard. Results: Passive 6MWT, which is the maximum 6-minute step count derived from daily accelerometer data (Fig 1), is strongly correlated with the reference standard (R=0.7501, P<0.0001, N=30) (Fig 2). Further analysis (Fig 2) reveals that regardless of the duration of the step count, the digital measures consistently have strong correlations with the reference standard, with the highest correlation obtained by Passive 10MWT (R=0.7746, P<0.0001, N=30). Conclusions: Early data highlights that accelerometer data collected during daily activities appears to indicate functional capacity of HF patients. Continued data will validate digital measures against various patient outcomes. Fig 1 Aggregation of Passive 6MWT from step count recorded during daily activities Fig 2 Correlation between accelerometer-derived passive step count digital measures and distance manually measured during baseline investigator-guided 6MWT as reference standard (N=30)

The field of cardiac electrophysiology has been on the cutting edge of advanced digital technologies for many years. More recently, medical device development through traditional clinical trials has been supplemented by direct to consumer products with advancement of wearables and health care apps. The rapid growth of innovation along with the mega-data generated has created challenges and opportunities. This review summarizes the regulatory landscape, applications to clinical practice, opportunities for virtual clinical trials, the use of artificial intelligence to streamline and interpret data, and integration into the electronic medical records and medical practice. Preparation of the new generation of physicians, guidance and promotion by professional societies, and advancement of research in the interpretation and application of big data and the impact of digital technologies on health outcomes will help to advance the adoption and the future of digital health care.