Personalized app-based coaching for improving physical activity in heart failure with preserved ejection fraction patients compared with standard care: rationale and design of the MyoMobile Study.

Aims: Patients suffering from heart failure with preserved ejection fraction (HFpEF) often exhibit a sedentary lifestyle, contributing to the worsening of their condition. Although there is an inverse relationship between physical activity (PA) and adverse cardiovascular outcomes, the implementation of Class Ia PA guidelines is hindered by low participation in supervised and structured programmes, which are not suitable for a diverse population of HFpEF patients. The MyoMobile study has been designed to assess the effect of a 12-week, app-based coaching programme on promoting PA in patients with HFpEF. Methods and results: The MyoMobile study was a single-centre, randomized, controlled three-armed parallel group clinical trial with prospective data collection to investigate the effect of a personalized mobile app health intervention compared with usual care on PA levels in patients with HFpEF. Major inclusion criteria were age ≥ 45 years, a diagnosis of HFpEF, LVEF > 40%, and current HF symptoms (NYHA Class I-III). Major exclusion criteria included acute decompensated HF, non-ambulatory status, recent acute coronary syndrome or cardiac surgery, alternative diagnoses for HF symptoms, active cancer treatment, and physical or medical conditions affecting mobility. Participants were recruited from hospitals, general practices, and practices specialized in internal medicine and cardiology in the Rhine-Main area, Germany. Participants underwent an objective 7-day PA measurement with a 3D accelerometer (Dynaport, McRoberts) at screening and after the 12-week intervention period. Following the screening, eligible participants were randomized into one of three groups: standard care (PA consulting), the intervention arm with app-based PA tracking and coaching, or the intervention arm with tracking but without coaching. The primary efficacy endpoint was the change in average daily step count between the average step count at baseline and at the end of the intervention, comparing standard care to a 12-week app-based PA coaching intervention. Conclusion: Exercise intolerance is a primary symptom in HFpEF patients, leading to poor quality of life and HF-related adverse outcomes due to physical inactivity. The MyoMobile study was designed to investigate the use of app-based coaching to improve PA in patients with HFpEF with a personalized, home-based intervention, focusing on simple step counts for flexibility and ease of integration into daily routines. Clinical trial registration: URL: https://clinicaltrials.gov/ct2/show/NCT04940312. Unique identifier: NCT04940312.