RESUMO
Chronic heart failure (CHF) is one of the most common diseases with a prevalence of 1-2% in adults, disproportionately affecting the elderly. Despite consistent drug therapy, physical activity (PA) is an integral part of current guidelines. Yet adherence to regular PA and exercise interventions is poor and potential predictors and barriers to PA remain elusive. We examined the effects of a telemonitoring-based exercise intervention in 699 CHF patients in a prospective, randomized-controlled (1:1), multicenter trial. The study was registered in the German Clinical Trials Register under DRKS00019022 on 28.05.2020. For both, the exercise and control group, self-reported PA (MET*h/week) increased and sedentary behavior declined during the 12-month intervention period. In the exercise group, daily step count as analyzed via activity trackers remained stable (pre: 6459 [4016] steps/day, post: 6532 [3858] steps/day; p = 0.621). The average number of completed exercise instruction videos provided via an online application was 1.50 [1.44] videos/week at the beginning and gradually decreased to 1.00 [1.50] videos/week; p < 0.001). Multivariate regression model revealed that exercise-related PA (MET*h/week) and exercise capacity (Wmax) at baseline, CHF severity, atrial fibrillation and age predicted changes in self-reported exercise-related PA (R2 = 0.396). Furthermore, the BMI and the average number of completed videos per week at baseline were associated with the change in completed videos over the course of the study (R2 = 0.251). Our results show the influence of certain baseline characteristics as barriers and predictors of PA progression. Therefore, exercise programs should pay attention to patients' individual conditions to set achievable goals, and eventually affect the adherence and sustainability of exercise-focused interventions.