Cognitive behavioural therapy for insomnia (CBT-I) in patients with coronary heart disease: a protocol for a randomized controlled trial with six months follow-up
Authors: Pekkola Pacheco A , Munkhaugen J M , Hrubos-Strom H , Klungsoyr O , Kvaerner K J , Stome L N , Papageorgiou C , Dammen T 
Published: June 2024

Abstract

Background
Chronic insomnia disorder, defined as difficulty initiating or maintaining sleep, or early morning awakening, ≥3 times/week for ≥3 months, causing daytime consequences, affects up to 45% of patients with coronary heart disease (CHD). This condition increases the risk of adverse cardiovascular outcomes and impairs quality of life, but remains undiagnosed and untreated in this patient group. Sleep has recently been recognized by the ESC and the AHA as a crucial part of cardiovascular health, highlighting the need for treatment of inadequate sleep. Cognitive-behavioral therapy for insomnia (CBT-I) is the gold standard for treating chronic insomnia, but its efficacy has not been investigated in patients with CHD without heart failure.

Purpose
To investigate the effects of CBT-I on chronic insomnia in patients with CHD, identify factors influencing treatment response, and potential pathophysiological and psychological correlates in terms of insomnia symptom change. We will also simulate the socioeconomic effects of the intervention prior to available outcome data.

Methods
We will conduct a randomized controlled trial comparing nurse-delivered, protocol-driven, group-based CBT-I over the course of five weeks (Figures 1 & 2) with sleep hygiene advice provided in a booklet as a control condition. In all, we will randomize 64 patients hospitalized with a coronary artery event during the preceding 4 years and who fulfil the diagnostic criteria for chronic insomnia. The study has power to detect a 25% absolute reduction in the primary outcome defined as no longer meeting the criteria for insomnia as assessed by the Bergen Insomnia Scale. Assessments pre-, post-intervention and at six months follow-up include insomnia diagnosis and severity, daytime symptoms (e.g., sleepiness, fatigue), anxiety, depression, metacognitions, quality of life, and blood and hair sampling for measures of inflammation, glycemic control and chronic cortisol exposure. Objective and subjective sleep variables will be assessed by actigraphy and sleep diaries. We will also interview a sample of patients as part of a qualitative study to explore their experience of treatment. A simulation of socioeconomic outcomes will be based on productivity loss and health service utilization.

Results
The first patient will be randomized in Q2 2024 and we expect the end of study to be Q4 2025. Results will provide new knowledge into the effects of CBT-I in patients with CHD and chronic insomnia, potentially underpinning the implementation of improved care strategies through enhanced sleep management, and may elucidate potential mechanistic pathways linking chronic insomnia and poor CVD outcomes.

Conclusion
Treating chronic insomnia in CHD patients requires further investigation and this will be the first trial to assess the effectiveness of CBT-I in CHD patients without heart failure. The trial will provide new insights regarding the impact of CBT-I on chronic insomnia in patients with CHD. Study overview. Overview of CBT-I intervention.