Home-Based, Digital Intervention to Increase Physical Activity in Patients with the Fontan Circulation

Patients who undergo cardiac surgeries to establish the Fontan circulation (FC) suffer from lifelong complications and early mortality. Engaging in physical activity (PA) may help to counteract these negative consequences. Youth with the FC engage in less physical activity (PA) than their peers and demonstrate decreased aerobic performance and lower skeletal muscle mass portending worse clinical outcomes. We now know that patients with the FC can safely engage in PA and improve their aerobic exercise performance in hospital-based exercise programs. Unfortunately, these programs are highly selective, costly, and inconvenient. Digital health applications can mitigate these barriers by remotely promoting PA beyond the point of care, especially with caregiver support. However, gaps in knowledge remain about whether a home-based digital intervention can 1) increase PA and 2) improve aerobic performance and increase skeletal muscle mass and muscle strength, in youth with the FC. Thirdly, it is not known how individual, family and neighborhood level factors influence the effectiveness of a home-based PA intervention. Thus, there is a critical need to develop and test innovative digital interventions to improve PA and clinical outcomes among all youth with the FC. The study team’s objective is to evaluate the efficacy of a digital intervention to increase PA and clinically relevant measures of physical fitness in youth with the FC. To accomplish this, the team proposes a randomized controlled trial with three specific aims. A wrist-worn physical activity tracker will be given to all participants, but they will be randomized to “enhanced usual care” (tracker plus standard encouragement to exercise) or a digital PA intervention for 6-months. The intervention arm will include: (1) personalized aerobic-based physical activity, (2) personalized resistance exercise sessions, and (3) financial and non-financial engagement strategies, targeting youth and caregivers. These intervention components will be delivered using an advanced mobile health informatics platform. Clinical assessments will be made at baseline, 6 months, and 12 months. Under aim 1, we will determine if the multi-component digital intervention increases PA levels in youth with the FC. Under aim 2, we will determine if the intervention leads to improvements in physical fitness outcomes (aerobic capacity, muscle mass, and strength). Finally, under aim 3, we will test whether medical, neurodevelopmental and/or sociodemographic factors, are associated with the efficacy of the digital intervention, using qualitative and quantitative approaches. It is anticipated that the digital intervention will significantly increase PA and improve physical fitness. Further, multi-level factors will be identified that associate with the efficacy of the intervention, thus providing the foundation for future implementation trials. These findings will lead to the integration of digital PA interventions for youth with a FC in the pediatric cardiology clinical setting.