Circadian variation of myocardial infarction onset in patients with sleep apnea

Abstract

Introduction Sleep apnea (SA) has a high prevalence in patients with acute coronary syndrome. Acute nocturnal pathophysiological responses to SA, including sympathetic activation, hypoxemia and increased coagulation, may increase the risk of nocturnal myocardial infarction (MI). There is limited evidence about circadian variation of onset of MI on dependence of having SA. Therefore, we examined the day- night variation of onset of MI in acute MI patients. Materials and methods We prospectively studied 782 consecutive patients admitted to the hospital, where primary percutaneous coronary intervention is the standard of care in the treatment of acute MI, with the diagnosis of acute MI. All subjects underwent sleep evaluations using a portable diagnostic device after at least 48 h post-admission, provided they were in a stable condition. The median duration from hospital admission to overnight sleep study was 4 days (range 2–14 days). Using the apnea- hypopnea index (AHI), groups were defined as patients without SA ( 30 events/hour). Results One hundred and seventy-five patients were eliminated from the final analysis due to the poor quality of their sleep study. Therefore, our final sample was represented by 607 patients. The day- night variation of the MI onset in all groups of SA patients was similar to that observed in non-SA patients. From 6 AM to 12 PM, the frequency of MI was higher in both SA and non-SA patients, as compared to the interval from 12AM to 6AM (all p Conclusion Peak time of MI onset in SA patients was between 6AM to noon, similar to that in the general population. Acknowledgements Supported by European Regional Development Fund – Project FNUSA-ICRC (No. CZ.1.05/1.1.00/02.0123) and by European Social Fund within the project ICRC Human Bridge – Support of Study Stays of Czech Researchers Abroad: Young Talent Incubator (No. CZ.1.07/2.3.00/20.0022).