Impact of Obstructive Sleep Apnea and Continuous Positive Airway Pressure Therapy on Outcomes in Patients With Acute Coronary Syndrome: The OSA-ACS Project

Obstructive sleep apnea (OSA) is an increasingly common chronic disorder in adults that has been strongly associated with various forms of cardiovascular disease. Compared to the general population, OSA occurs more often in patients with acute coronary syndrome (ACS). Although percutaneous coronary intervention (PCI) is nowadays part of standard therapy and optimal medical therapy has been used to manage traditional risk factors, the long-term cardiovascular outcomes after index ACS remain suboptimal.

Some preliminary data suggest OSA is associated with higher risk of subsequent cardiovascular events in ACS patients. However, the study population was heterogeneous and these studies were not done in the context of new-generation drug-eluting stents and intensive antiplatelet therapy, thus precluding definite conclusions. Furthermore, a cardioprotective role of OSA in the context of acute myocardial infarction (AMI), via ischemic preconditioning, has also been postulated.

Due to the inconsistent evidence, the investigators performed a large-scale, prospective cohort study to delineate the whole picture of the association of OSA with short- and long-term outcomes of patients with ACS. Whether treatment of OSA (eg. continuous positive airway pressure (CPAP)) would prevent these events will also be evaluated. Moreover, the investigators will assess the potential mechanisms of OSA-induced atherosclerosis and myocardial injury in ACS patients.