Over 50% of patients participating in cardiac rehabilitation (CR) experience poor sleep and/or, closely related, psychological stress. Although stress management interventions are generally available, they are typically underutilised in CR, and sleep remains an underaddressed component within CR. This is concerning, as poor sleep and stress not only reinforce each other but are also associated with poorer cardiovascular health and lower quality of life. Therefore, the primary aim of the OPtimising CArdiac REhabilitation by REfining Sleep and STress (RESST) study is to investigate the (cost-)effectiveness of adding a behavioural intervention targeted at improving sleep and managing stress during CR (RESST intervention) on sleep and psychological stress. Furthermore, the study aims to explore the (bidirectional) associations between sleep, stress and lifestyle behaviours.

This parallel-arm multicentre randomised controlled trial will include 200 CR patients across 3 major CR centres in the Netherlands who experience poor sleep and/or stress. Patients will be randomised in a 1:1 ratio to standard CR or standard CR with the RESST intervention. Standard CR is a structured programme combining exercise, lifestyle guidance and risk management. On top of standard CR, the RESST intervention consists of 5 in-person group sessions targeting sleep and stress and is based on Acceptance and Commitment Therapy and Cognitive Behavioural Therapy. Primary outcomes are accelerometer-assessed and self-reported sleep and perceived stress. Secondary outcomes include quality of life, psychosocial well-being, chronic stress biomarkers (hair cortisol and cortisone), momentary fatigue, momentary stress and physical activity. Linear mixed models will be used to assess changes in outcomes at 3-month (after intervention and/or CR completed) and 6-month follow-up. The momentary data collected with ecological momentary assessment and accelerometry will be analysed using multilevel linear mixed models to explore the (bidirectional) relationship between sleep, stress and other lifestyle components such as physical activity.

This study was approved by the ethics committee of Erasmus MC, Erasmus University Medical Centre, Rotterdam, the Netherlands (MEC-2024-0238). The findings will be disseminated through publications in peer-reviewed journals, presentations at academic conferences and professional and patient publications.

NCT06505109.