Insomnia is associated with an increased risk for recurrent major adverse cardiovascular events (MACE), according to findings of a recent follow up study of patients with coronary heart disease and nearly half of them suffer from insomnia.¹

In this prospective study reported in the journal Sleep Advances, the researchers from the University of Oslo in Norway enrolled 1068 patients 16 months (average) after myocardial infarction and/or coronary revascularization procedure either stenting or cardiac bypass surgery and followed them for an average period of 4.2 years to establish an association between clinical insomnia and MACE in outpatients with coronary heart disease (CHD). The Bergen Insomnia Scale (BIS) questionnaire was used to measure clinical insomnia. Baseline coronary risk factors (such as diabetes, physical activity, waist circumference, LDL cholesterol, BP, CRP, smoking) and comorbidities (such as stroke, transient ischemic attack, peripheral artery disease, kidney failure) were also assessed. Only 21% of the participants were female.

Forty-five percent of the study population had insomnia at the time of their enrollment in the study and 24% reported using sleep medication in the past week. A total of 364 MACE were recorded in 225 patients.

Patients with clinical insomnia were at higher risk of developing recurrent MACE with a relative risk of 1.62. This risk was significant even after adjusting for coronary risk factors, comorbid conditions, anxiety, depression in multi-adjusted analysis (RR 1.4). Patients who smoked had 27% higher risk of MACE followed by low physical activity with 21% higher risk. Notably in this study, insomnia accounted for 16% of recurrent MACE.

According to the authors, “this is the first study to detect a prospective association between a self-report diagnosis of clinical insomnia and MACE in outpatients with CHD”. In attributable risk fraction analyses, insomnia emerged as the third most important factor leading to increased risk of cardiac events after smoking and sedentary life, which are considered as traditional risk factors for heart disease. Presence of insomnia therefore may be considered a risk factor and predictive of MACE in these patients. Hence, it becomes imperative to assess them for insomnia and manage it well to ameliorate their risk of recurrent cardiac events and for better patient outcomes.

Reference 

1. Frøjd LA, et al. Insomnia as a predictor of recurrent cardiovascular events in patients with coronary heart disease, SLEEP Advances. 2022;3(1):zpac007. https://doi.org/10.1093/sleepadvances/zpac007