Safety and efficacy of a medically guided home-based exercise program in adults with congenital heart disease: a proof-of-concept study
Authors: Vanreusel I , Paelinck B , Van Craenenbroeck E , Segers V , Van Berendoncks A , Hens W 
Published: June 2024

Abstract

Background and Aim
Exercise capacity (EC) is reduced in patients with congenital heart disease (CHD). In general, physicians tend to be too cautious in their advice on exercise in CHD. However, participation in regular exercise is not only beneficial for CHD patients’ physical fitness, psychological well-being, and social interaction, but also has a positive effect on the future risk of acquired heart disease. Therefore, improving EC is worthwhile in all CHD patients, but knowledge on existing programs is lacking. Exercise programs are often supervised and center-based, leading to time and transportation barriers. Therefore, we wanted to investigate the safety, feasibility, and efficacy on EC of a medically guided 16-week home-based aerobic exercise training program (HBex) in adults with CHD.

Methods
Adults with different types of CHD who were able to comply with an exercise training program, were randomized into conventional care versus a medically guided 16-week HBex. In the conventional care arm, patients were allowed to be physically active and received general lifestyle advice, based on the current physical activity guidelines. In the HBex arm, each participant received an individual rehabilitation schedule guided by a smartphone application consisting of a combination of resistance and endurance training in which the patient cycled for 30-45 minutes on an exercise bike at home three times a week. This cardio workout was combined with a strength exercise program at home. During each training session, the heart rate (HR) was continuously recorded using a chest strap and the target HR zone was set in the device, allowing for feedback by the activity tracker during and after the exercise session. All patients underwent a cardiopulmonary exercise test (CPET) before randomization and after 16 weeks. The change in EC was analyzed in 46 adults with CHD who performed a maximal CPET (RER ≥ 1.05) on both study visits.

Results
Initially, the conventional care arm consisted of 21 and the exercise arm of 25 patients, 9 of whom did not comply to the training program (&lt; 70% of the prescribed activity, i.e. dropout of 36%). EC was initially reduced (percent-predicted peak oxygen consumption &lt; 85%) in 17 of the 37 remaining patients and improved significantly in the HBex group, but not in the conventional care arm. Repeated measures ANOVA showed that the change over time was significantly larger in the HBex compared to the conventional care group (Figure 1). Importantly, in both groups, there were no serious adverse events.

Conclusion
Our medically guided 16-week HBex was safe, feasible and resulted in improved EC in adults with CHD. Nevertheless, compliance remains a major concern. There is therefore a need for further larger randomized controlled trials on the effect of different exercise modalities, as well as for more insights into the barriers to exercise in order to motivate CHD patients to be physically active.