Clinical Research
Myocardial Infarction
Day–Night Variation of Acute Myocardial Infarction in Obstructive Sleep Apnea

https://doi.org/10.1016/j.jacc.2008.04.027Get rights and content
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Objectives

This study sought to evaluate the day–night variation of acute myocardial infarction (MI) in patients with obstructive sleep apnea (OSA).

Background

Obstructive sleep apnea has a high prevalence and is characterized by acute nocturnal hemodynamic and neurohormonal abnormalities that may increase the risk of MI during the night.

Methods

We prospectively studied 92 patients with MI for which the time of onset of chest pain was clearly identified. The presence of OSA was determined by overnight polysomnography.

Results

For patients with and without OSA, we compared the frequency of MI during different intervals of the day based on the onset time of chest pain. The groups had similar prevalence of comorbidities. Myocardial infarction occurred between 12 am and 6 am in 32% of OSA patients and 7% of non-OSA patients (p = 0.01). The odds of having OSA in those patients whose MI occurred between 12 am and 6 am was 6-fold higher than in the remaining 18 h of the day (95% confidence interval: 1.3 to 27.3, p = 0.01). Of all patients having an MI between 12 am and 6 am, 91% had OSA.

Conclusions

The diurnal variation in the onset of MI in OSA patients is strikingly different from the diurnal variation in non-OSA patients. Patients with nocturnal onset of MI have a high likelihood of having OSA. These findings suggest that OSA may be a trigger for MI. Patients having nocturnal onset of MI should be evaluated for OSA, and future research should address the effects of OSA therapy for prevention of nocturnal cardiac events.

Key Words

obstructive sleep apnea
myocardial infarction
day–night variation

Abbreviations and Acronyms

AHI
apnea–hypopnea index
BMI
body mass index
BP
blood pressure
MI
myocardial infarction
OSA
obstructive sleep apnea
PSG
polysomnography
SCD
sudden cardiac death

Cited by (0)

Supported in part by the Respironics Foundation for Sleep and Respiratory Research and National Institutes of Health grants HL65176 and M01-RR00585. Dr. Sert Kuniyoshi is supported by American Heart Association grant 06-15709Z, a Perkins Memorial Award from the American Physiological Society, and the Espirito Santo Science and Technology Foundation. Dr. Lopez-Jimenez is supported by the American Heart Association. Dr. Kara is supported by an unrestricted educational grant from General Electric (Europe). Dr. Somers serves as a consultant for ResMed and Respironics, and has spoken at meetings sponsored by Respironics, ResMed, and Medtronic; he has served as consultant for GlaxoSmithKline, Sepracor, and Cardiac Concepts; he has received research grants from the ResMed Foundation, the Respironics Sleep and Respiratory Research Foundation, Sorin, Inc., and Select Research; and he works with Mayo Health Solutions and iLife on intellectual property related to sleep and to obesity.