Beyond modality: unaddressed variables and comorbidities in exercise interventions for coronary artery disease

This commentary refers to ‘Exercise type and settings, quality of life and mental health in coronary artery disease: a network meta-analysis’, by A. Toval et al., https://doi.org/10.1093/eurheartj/ehae870 and the discussion piece ‘New venues to study the effects of exercise on quality of life and mental health in coronary artery disease’, by E. A. Bakker et al., https://doi.org/10.1093/eurheartj/ehaf489. I read with great interest the recent study by Toval et al.1 on the comparison between in-person and home-based exercise interventions in coronary artery disease (CAD) patients. The authors present a comprehensive meta-analysis, and their contribution is valuable in advancing the understanding of exercise interventions in this patient population. However, I would like to highlight two important shortcomings that require further attention. First, the analysis of exercise settings appears somewhat simplistic. The authors compared in-person exercise with home-based exercise, yet they did not account for several critical factors that may influence the effectiveness of these interventions. Specifically, factors such as the duration of the exercise program, the frequency of sessions, and the type of supervision provided—all of which are known to significantly impact exercise outcomes.2,3 For instance, a meta-analysis by Chen et al.2 observed improvements in cardiac function and cardiovascular risk factors in CAD patients following exercise interventions lasting over 12 weeks, with weekly durations of 60–90 min. In addition, Toval et al.3 found that engaging in supervised exercise training could lead to a modest enhancement in the health-related quality of life among individuals with CAD.3 Therefore, the exclusion of these variables makes it difficult to determine whether the outcomes observed in the study were solely attributable to the exercise modality (in-person vs. home-based) or influenced by the intensity and structure of the interventions.