Research in context
Evidence before this study
Obstructive sleep apnoea (OSA) is a common condition among patients with cardiovascular disease, affecting 40–60% of such patients. Because the risk of recurrent cardiovascular events among these patients remains high despite contemporary therapies, CPAP could be a useful additional treatment for the prevention of these events. We searched PubMed with the terms “obstructive sleep apnea”, “acute coronary syndrome”, “CPAP treatment”, and “secondary prevention” for systemic reviews and randomised controlled trials published up to Jan 1, 2019. Previous randomised controlled trials have shown that the treatment of OSA with CPAP is associated with a reduction in blood pressure, left ventricular mechanical overload, and arrhythmia. In addition, observational clinical studies have shown that the use of CPAP is associated with lower prevalence of cardiovascular complications and of death from cardiovascular causes. Three previous randomised controlled trials have directly addressed cardiovascular clinical endpoints in patients who have suffered a major cardiovascular event and the authors observed a neutral effect of CPAP treatment for secondary cardiovascular prevention.
Added value of this study
Our findings indicate that the use of CPAP therapy, compared with usual care alone, had no positive effect on the prevention of recurrent major cardiovascular events in patients with OSA and acute coronary syndrome. Moreover, the presence of OSA was not associated with an increased prevalence of cardiovascular events.
Implications of all the available evidence
The results of this secondary prevention trial in adults with acute coronary syndrome and OSA, supported by further studies, contribute to understanding the observed neutral effect of CPAP treatment for secondary cardiovascular prevention.