A Cardiac-rehab Based Behavior-change Intervention To Reduce Sedentary Behavior In Coronary Artery Disease Patients

PURPOSE: A sedentary lifestyle is highly prevalent among patients with coronary artery disease (CAD), so targeted interventions aiming to reduce sedentary time (ST) may hold great promise. We examined the long-term effect of the SIT LESS intervention on changes in ST in CAD patients enrolled in cardiac rehabilitation (CR). METHODS: CAD patients participating in CR at 2 hospitals were included in this parallel-group randomized controlled trial (1:1 randomization, stratified for gender and hospital). The control group participated in a usual care exercise-based CR program, whereas SIT LESS participants additionally received a 12-week behavior change intervention consisting of education, goal-setting, motivational interviewing, and telemonitoring. The primary outcome was the change in objectively measured ST from pre-CR to immediately post-CR and 3-months post-CR, whereas the outcome assessment was blinded. Secondary outcomes included changes in ST characteristics, physical activity characteristics, quality of life, patients’ competence for self-management, physical function, and cardiovascular risk factors. Outcome analyses were performed on an intention-to-treat basis using a constrained linear mixed-model. RESULTS: 212 out of 237 approached patients were included (89%; SIT LESS: n = 108, Control: n = 104). Patients (77% male) were 63 ± 10 years and primarily diagnosed with myocardial infarction (78%). ST was 11.1 (95% confidence interval (95% CI): 10.9; 11.3) h/day at pre-CR. Greater reductions in ST were found for SIT LESS compared to control at post-CR (-1.7 (95% CI: -2.0; -1.4) versus -1.1 (95% CI: -1.4; -0.8) h/day, pinteraction = 0.009), but these differences attenuated at 3 months post-CR (-1.4 (95% CI: -1.8; -1.1) versus -1.3 (95% CI: -1.6; -1.0) h/day, pinteraction = 0.61). The increase in light intensity physical activity (LIPA) from pre- to post-CR was larger for SIT LESS compared to control (0.39 (95% CI: 0.06; 0.71) h/day, pinteraction = 0.020). Changes in secondary outcomes did not differ among groups. CONCLUSION: The SIT LESS intervention transiently reduces ST and increases LIPA for patients with CAD participating in CR, but group differences were attenuated at 3 months post-CR. These findings highlight the challenge to induce sustainable behavior changes in patients with CAD. Dutch Heart Foundation