DOI: 10.1161/circ.148.suppl_1.15144 ISSN: 0009-7322

Abstract 15144: The Heartline Experience: Can Digital Health Technology Trials Achieve Long-Term Participant Engagement?

Janeta Nikolovski, Ann Marie Navar, Steve Steinhubl, Katie Baca-Motes, Anne B Curtis, Eric D Peterson, Dhanunjaya Lakkireddy, Michael Tarino, Stephanie Juan, CV Damaraju, Dereck Wentworth, Mithun Patel, Cammie Tavakoli, Charles M Gibson, John Spertus
  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine

Background: Digital health technologies can potentially streamline clinical research and reach broad and diverse populations, yet they often fall short to achieve long-term participant engagement.

Research Question: Can long-term participant engagement in a large, direct-to-participant randomized trial using an entirely decentralized trial platform be achieved?

Methods: Heartline ( was designed to test the impact of a mobile app-based heart health program with the electrocardiogram (ECG) and Irregular Rhythm Notification (IRN) features on Apple Watch for early diagnosis, treatment, and outcomes of atrial fibrillation (AF). The custom app collected electronic patient-reported outcomes (ePROs) and incorporated engagement strategies based on behavioral science principles and features relevant to the target study population, including a simple interface and actions, weekly curated health education, and points-based incentives. Participants who received an IRN from their Apple Watch were prompted to take an ECG and follow up with their healthcare provider (HCP).

Results: From 02/2020 to 12/2022, Heartline enrolled 34,245 US participants ≥65 years of age. To date, 80% and 76% of the study population used the app at least monthly after 1 and 2 years, with weekly engagement rates of 68% and 66%, respectively ( Figure ). ePRO response rates were 88% at 1 year and 91% at 2 years. Of those receiving an IRN, 85% took an ECG recording and 71% reported follow up with their HCP.

Conclusions: The Heartline study achieved high rates of sustained, longitudinal engagement, with >75% of the study population remaining engaged over 2 years and >90% completing ePROs, representing substantially higher engagement rates than prior remote digital health studies. A combination of strategies was used to promote engagement in Heartline. Further work to identify the key drivers of engagement will inform future decentralized trials and digital therapeutics.

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