Remote 3-week Booster Intervention to Reduce Sedentary Time in Patients With Coronary Artey Disease

The goal of this clinical trial is to learn about the effect of a booster program aiming to lower daily sitting time (SIT LESS Booster program) compared to usual care in patient with coronary heart problems. The main question it aims to answer is: What is the effect of the SIT LESS Booster on sedentary time and physical activity levels in patient with coronary artery disease who participated in cardiac rehabilitation.

Participants will be randomized into 2 groups:

1. Control group who receives usual care;
2. SIT LESS Booster group who receives usual care + a remote 3-week SIT LESS Booster program.

Objectively measured changes in daily sitting time from pre- to post SIT LESS Booster will be compared between groups to see if participants in the SIT LESS Booster group are able to reduce daily sedentary time more compared to participants in the control group.

High levels of sedentary time (ST) are observed in patients with coronary artery disease (CAD) and are associated with adverse health outcomes. Behavioural interventions targeting ST are effective in the short-term, but effects seem to diminish at long-term follow-up. Short-term (telephonic) booster programs can induce sustainable physical activity behavioural changes. However, the effects of a booster ST reduction program are unknown. Therefore, we aim to assess the effect of the SIT LESS Booster on sedentary time and physical activity levels in patient with coronary artery disease who participated in cardiac rehabilitation.

All participants took already part in a special cardiac rehabilitation program aiming to lower daily sitting time between May 2021 and April 2022. For this study, they will be randomized into 2 groups:

1. Control group who receives usual care;
2. SIT LESS Booster group who receives usual care + a remote 3-week SIT LESS Booster program.

The SIT LESS Booster program consists of:

* Telephone consultation in which the participants are informed about the negative effects of high daily sitting time, discuss personal goals to lower daily sitting time and make an action plan to reach the goals.
* Use of a pocket-worn activity tracker to get insight in their own daily sitting time. The activity tracker can be connected to a smartphone application. Besides, the activity tracker buzzes when a person sits more than 30 consecutive minutes as a reminder to stand up.
* Weekly telephone calls to discuss the progress regarding their personal sit less goals.

In both groups, daily sitting time will be measured at the start of the study and at the end of the SIT LESS Booster program using the ActivPAL.

Data analysis will be conducted using R and p-values of \<0.05 will be considered statistically significant. Changes in daily ST will be compared between groups using a linear mixed model.

This trial was approved by the Medical Ethics Committee of the Radboud university medical center (NL72604.091.20)

Eligibility Criteria:
Inclusion Criteria:

• Participation in the SIT LESS intervention group of the SIT LESS study

Exclusion Criteria:

* Unable to give informed consent
* Wheelchair-bounded / not physically able to stand or walk.
* Language barrier
* Coronary arterial bypass graft surgery expected within 8 weeks after inclusion
* New York Heart Association class III or IV heart failure
* Participation in another interventional study targeting SB or PA