Acute coronary syndrome (ACS) is a condition used to describe sudden, reduced blood flow to the heart. Though the prognosis of ACS has significantly improved, substantial morbidity and mortality remain to be common. This study aims to examine the effect of obstructive sleep apnea (OSA) and its treatment with continuous positive airway pressure (CPAP) in patients with ACS.

This multicenter, parallel-group, randomized, open-label, controlled trial included a total of 2,551 patients aged 18 years or older with ACS. Of 2,551 patients, 1,264 had OSA and were assigned in a 1:1 ratio to CPAP treatment with usual care (CPAP group, n= 633) or usual care alone (UP group, n=631). Six hundred three patients who did not have OSA were assigned to the reference group. The primary outcome of the study was the prevalence of a composite of cardiovascular events, including myocardial infarction (MI), non-fatal stroke, heart failure hospitalization, or death.

During the median follow-up of 3.35 years, the prevalence of cardiovascular events was identical between patients in the CPAP and UC groups (16% vs. 17%). The prevalence of cardiovascular events was also similar between patients in the reference and UC groups (15% vs. 17%). The prevalence of cardiovascular events was not associated with OSA severity or CPAP compliance.

The research concluded that among ACS patients, the presence of OSA was not associated with the risk of cardiovascular events.