Sleep impairment and prognosis of acute myocardial infarction: a prospective cohort study.
OBJECTIVE
Impaired sleep is an established risk factor for the development of cardiovascular disease, whereas less is known about how impaired sleep affects cardiovascular prognosis. The aim of this study is to determine how different aspects of impaired sleep affect the risk of case fatality and subsequent cardiovascular events following first-time acute myocardial infarction (AMI).


METHODS
Prospective cohort study.


METHODS
The Stockholm Heart Epidemiology Program, Sweden.


METHODS
There were 2,246 first-time AMI cases.


RESULTS
Sleep impairment was assessed by the Karolinska Sleep Questionnaire, which covers various indices of impaired sleep: disturbed sleep, impaired awakening, daytime sleepiness, and nightmares. Case fatality, defined as death within 28 days of initial AMI, and new cardiovascular events within up to 10 y of follow-up were identified through national registries. In women, disturbed sleep showed a consistently higher risk of long-term cardiovascular events: AMI (hazard ratio [HR] = 1.69; 95% confidence interval [CI] 0.95-3.00), stroke (HR = 2.61; 95% CI: 1.19-5.76), and heart failure (HR = 2.43; 95% CI: 1.18-4.97), whereas no clear effect of impaired sleep on case fatality was found in women. In men, a strong effect on case fatality (odds ratio = 3.27; 95% CI: 1.76-6.06) was observed in regard to impaired awakening; however, no consistent effect of impaired sleep was seen on long-term cardiovascular prognosis.


CONCLUSIONS
Results suggest sex-specific effects of impaired sleep that differ by short- and long-term prognosis. Sleep complaints are frequent, easily recognizable, and potentially manageable. Evaluation of sleep complaints may, even if they represent prognostic markers rather than risk factors, provide additional information in clinical risk assessment that could benefit secondary cardiovascular prevention.
Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark ; The Copenhagen Stress Research Center, Copenhagen, Denmark.
Alice
A
Clark
Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Theis
T
Lange
Department of Public Health Sciences, Division of Social Medicine, Karolinska Institute, Stockholm, Sweden ; Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
Johan
J
Hallqvist
Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Glostrup Hospital, Copenhagen, Denmark.
Poul
P
Jennum
Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark ; The Copenhagen Stress Research Center, Copenhagen, Denmark.
Naja Hulvej
NH
Rod
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004325:Dreams; D005260:Female; D006333:Heart Failure / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis* / Q000401:mortality; D016017:Odds Ratio; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000150:complications*; D020521:Stroke / Q000150:complications; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology
cardiovascular disease; cohort study; myocardial ischemia; prognosis; recurrence; sleep impairment