Continuous positive airway pressure (CPAP) in addition to usual care did not prevent cardiovascular events in patients with moderate-to-severe obstructive sleep apnea and cardiovascular disease (CVD), according to a study published in the New England Journal of Medicine.
R. Doug McEvoy, MD, from the Adelaide Institute for Sleep Health and Flinders University, Australia, and colleagues conducted the Sleep Apnea Cardiovascular Endpoints (SAVE) study to evaluate the effectiveness of CPAP in 2717 adults between 45 and 75 years of age with moderate-to-severe sleep apnea and coronary or cerebrovascular disease.
The researchers randomly assigned the patients to receive CPAP treatment with usual care or usual care alone after a 1-week period during which the participants used sham CPAP. They defined the primary end point as death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for unstable angina, heart failure, or transient ischemic attack. They also measured secondary end points that included additional cardiovascular outcomes, health-related quality of life, snoring symptoms, daytime sleepiness, and mood.
The results revealed that the average duration of adherence to CPAP therapy was 3.3 hours per night, and the average number of apnea or hypopnea events per hour decreased from 29.0 events per hour to 3.7 events per hour.
After 3.7 years of follow-up, a primary event occurred in 17% of participants who received usual care with CPAP compared with 15.4% of patients who received usual care alone. The researchers did not observe additional significant cardiovascular outcomes, but CPAP significantly reduced snoring and daytime sleepiness and improved quality of life and mood.
“This study was not powered to provide definitive answers regarding the effects of CPAP on secondary cardiovascular end points, but there was no indication of a significant benefit with respect to any cause-specific cardiovascular outcome,” the study authors wrote.
- McEvoy RD, Antic NA, Heeley E, et al. CPAP for prevention of cardiovascular events in obstructive sleep apnea. N Engl J Med. 2016; doi: 10.1056/nejmoa1606599.