BRIDGE Trial: Embedding Consumer-grade mHealth Technologies Into Cardiac Rehabilitation

Phase II Cardiac Rehabilitation (CR) is an evidence-based secondary prevention program for patients with cardiovascular disease (CVD).The core components of comprehensive CR are well-established and include patient assessment, exercise training, physical activity (PA) promotion, health education, nutritional counseling, psychological support, and CVD risk management. Phase II CR programs generally offer three sessions per week in an outpatient center - known as center-based CR (CBCR) - and supplemental healthy lifestyle behaviors are encouraged in patients' daily living environments. Despite strong evidence supporting the effectiveness of CBCR, its impact is constrained by four main barriers: 1) patients often fail to maintain adequate physical activity on non-CR days; 2) many patients fail to attend all prescribed CR sessions while others prematurely discontinue the program; 3) many CBCR programs are exercise-centered, offering minimal attention to other core components (e.g. risk management); and 4) reach remains limited, with poor adherence to home-based recommendations. Data shows that up to 86.5% of CR participants fail to meet guideline-recommended weekly PA targets and remain largely inactive on non-CR days. Also, only 26.9% of participants completed the 36-session course of CBCR, while 56.7% attended at least 25 sessions - a threshold associated with significant health benefits. Additionally, standardized educational programs for CR participants are lacking across many healthcare systems, and it is reported that a lack of CR knowledge and low self-efficacy are significant barriers to CR adherence and PA regimen adherence. Many CR programs do not fully deliver all components of comprehensive CR, with a tendency to emphasize exercise training while providing less consistent attention to diet, medication adherence, and other risk management components. Innovative and scalable strategies that extend patient support beyond the clinic and reinforce behavior change are urgently needed to maximize the clinical benefits of CBCR.

Mobile health (mHealth) technologies, such as smartphones, apps, text messages, wearables, and other commercially available connected health devices, have gained popularity in recent years. These mHealth tools offer a promising adjunctive approach to traditional CBCR programs, helping overcome some of the existing challenges. Mobile apps and wearable activity trackers can facilitate more frequent self-monitoring in the community and encourage positive health behaviors, including self-management of CVD. Evidence shows that text messages (TMs) are associated with improvements in PA and medication adherence among different populations and support self-management of chronic conditions. Our recent systematic review published in The Lancet Digital Health demonstrates that provision of exercise-based CR at home facilitated by mHealth technologies is associated with significantly greater benefits in functional capacity and other health outcomes compared with usual care. These findings confirmed that mHealth can effectively enable patients to engage in CR-related behaviors outside formal outpatient settings. However, very few studies have evaluated mHealth as an adjunct to CBCR to extend behavioral support in people's daily living environments. The question of whether mHealth tools can meaningfully augment the effectiveness of CBCR remains largely underexplored. Additionally, prior studies have mainly tested research-developed apps that are not commercially available, thus limiting scalability and potential for real-world implementation. The effect of tailored theory-based TM programs combined with widely used commercial mHealth tools among CBCR participants remains underexplored.

To address these gaps, our study team has developed an mHealth intervention (BRIDGE) that integrates commercially available mHealth apps (Fitbit app and Withings app) and connected devices (Fitbit tracker, Withings BP and weight monitor) with individually tailored TMs selected from a study-developed TM library. BRIDGE intervention will augment CBCR by targeting multiple CR components, including exercise training, PA, heart-healthy diet, weight management, and CVD risk management.

The goal of the proposed project is to evaluate the feasibility, acceptability, and preliminary efficacy of the BRIDGE intervention in improving exercise capacity and self-reported health outcomes through a randomized controlled trial (RCT). A total of 30 CR participants will be recruited and randomized to one of two treatment groups: (1) CBCR alone, (2) CBCR + BRIDGE intervention.