The Prognostic Significance of Sleep and Circadian Rhythm for Myocardial Infarction Outcomes: Case-Control Study

Area of Science:

• Cardiology
• Sleep Medicine
• Chronobiology

Background:

• Myocardial infarction (MI) is a critical condition often associated with sleep disturbances and altered circadian rhythms.
• While premorbid sleep in MI patients is studied, post-MI sleep and circadian impacts on prognosis remain less understood.
• Actigraphy offers a potential tool for evaluating post-MI sleep and circadian rhythm to predict outcomes.

Purpose of the Study:

• To investigate the effects of sleep patterns and disrupted circadian rhythm on myocardial infarction (MI) prognosis.
• To utilize actigraphy and heart rate variability (HRV) for comprehensive patient assessment.
• To analyze nonparametric actigraphy data for quantifying circadian rhythm parameters.

Main Methods:

• Enrolled patients with MI in the ICU and age/gender-matched healthy controls.
• Employed actigraphy for sleep and circadian rhythm evaluation and HRV monitoring for autonomic function.
• Quantified rest-activity patterns using interdaily stability, intradaily variability, M10, L5, relative amplitude, and dichotomy index.
• Conducted 3- and 6-month follow-ups to assess prognosis and used statistical tests for group comparisons and correlation analyses.

Main Results:

• MI patients exhibited poorer sleep quality, including increased wake after sleep onset and reduced sleep efficiency compared to controls.
• MI patients showed significantly lower daytime activity and a more delayed and fragmented circadian rhythm.
• Disturbed circadian rhythm parameters, such as nighttime activity and M10/L5 timing, significantly correlated with patient prognosis.

Conclusions:

• Acute myocardial infarction (MI) patients demonstrate significantly impaired sleep and circadian rhythm compared to healthy individuals.
• Actigraphy revealed disturbed circadian rhythms in MI patients, characterized by reduced daytime activity and weak rest-activity patterns, correlating with prognosis.
• Assessing sleep and circadian rhythm post-MI is a valuable prognostic indicator warranting further investigation.