Central sleep apnea syndrome prevalence is high early after an acute coronary syndrome without heart failure or left ventricular dysfunction

Background Although the prevalence of obstructive sleep apnea (OSA) syndrome is high in patients with acute coronary syndrome (ACS), little is known about central sleep apnea (CSA) prevalence in these patients, especially if they have no left ventricular dysfunction. Furthermore, central apnea could be promoted by ticagrelor, a relatively new drug. Purpose To investigate the prevalence of central sleep apnea in patients without left ventricular dysfunction after an ACS. Methods All consecutive patients within 100 days after an ACS were included if they had left ventricular ejection fraction (LVEF) > 45%, no history of heart failure, systolic arterial pulmonary artery inferior to 45 mm Hg, no known history of sleep apnea, and if they were not receiving a sedative drug. After inclusion, patients underwent an overnight sleep study with a Nox T3 portable sleep monitor. Results Between May 1, 2018 and April 10, 2019, we included 50 consecutive patients 43 ± 24 days after an ACS (age 56.1 ± 10.5, male 54%, mean body mass index 28.6 ± 4.9, mean LVEF: 55.5 ± 4.9%). All of them were receiving a dual antiplatelet therapy: aspirin 100%, ticagrelor 85%, clopidogrel 10%, prasugrel 5%. 23 patients (46%) had a clinically significant (moderate to severe) apnea hypopnea index (AHI) > 15/h: CSA: 24%, OSA: 22%. Among them 13 (26%) had a severe sleep breathing disorder(AHI >30): CSA 16% OSA: 10%. The only favoring factor to have an AHI > 30 was timing for the sleep diagnostic test: 29 ± 24 days in patients with AHI > 30 versus 49 ± 22 days in the other patients, P = 0.01. The role of ticagrelor could not be assessed because nearly all of the patients received it. Conclusion As expected, OSA is frequent in coronary artery disease patients (early after ACS in this study). High prevalence of CSA was less expected. Our results suggest that, before looking for another (neurological) cause, confirmation of CSA should be done at least 2 months after the ACS.