Study objectives: We assessed whether excessive daytime sleepiness was associated with coronary plaque phenotype and subsequent adverse cardiovascular events.
Methods: Prospective cohort study. Intravascular ultrasound (IVUS) examination of the culprit coronary stenosis was performed. The Epworth Sleepiness Scale (ESS) questionnaire was administered, and the patients were divided into 2 groups-(1) sleepier and (2) less sleepy-based on the ESS score. Adverse cardiovascular outcomes were defined as cardiac death, myocardial infarction, stroke, unplanned revascularization, or heart failure admission.
Results: One hundred seventeen patients undergoing urgent or non-urgent coronary angiography were recruited. Compared with the less sleepy group (ESS ≤ 10, n = 87), the sleepier group (ESS > 10, n = 30) had higher serum levels of total cholesterol and of low-density-lipoprotein cholesterols (p < 0.05 for both). The IVUS examinations indicated coronary stenoses were longer in the sleepier group than in the less sleepy group (p = 0.011). The cumulative incidence of adverse cardiovascular events at 16-month follow-up was higher in the sleepier than the less sleepy group (12.5% versus 6.9%, p = 0.03). Cox regression analysis adjusting for age and smoking showed increased hazard of adverse cardiovascular events in sleepier group as compared to less sleepy group (HR = 3.44, 95% CI 1.01-11.72).
Conclusion: In patients presenting with coronary artery disease, excessive daytime sleepiness based on ESS > 10 was associated with longer culprit lesions and future adverse cardiovascular events.
Keywords: Sleepiness; coronary artery disease; intravascular ultrasound; outcomes.