Harlan M. Krumholz, MD, SM Reviewing McEvoy RD et al., N Engl J Med 2016 Aug 28;
In a multicenter trial, patients with cardiovascular disease and obstructive sleep apnea had no reduction in risk.
Continuous positive airway pressure (CPAP) is a common treatment for obstructive sleep apnea, a risk factor for cardiovascular disease. However, little is known about whether CPAP reduces cardiovascular risk. To shed light on this question, the Sleep Apnea Cardiovascular Endpoints (SAVE) investigators conducted an open-label randomized trial of patients from 89 centers in seven countries. Patients were eligible if they were 45 to 75 years old and were diagnosed with both moderate-to-severe obstructive sleep apnea and coronary artery or cerebrovascular disease.
After a run-in period, 2717 patients (mean age, 61; 81% men; mean body-mass index, 29 mg/kg2) were randomized to CPAP plus usual care or usual care alone. With a mean follow-up of 3.7 years, the primary endpoint (a composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure, acute coronary syndrome, or transient ischemic attack) was confirmed in 17.0% of the CPAP group and 15.4% of the usual-care group (hazard ratio, 1.10; 95% confidence interval, 0.91–1.32). There was no significant heterogeneity across subgroups. Sleepiness and other symptoms were favored by CPAP.
This study is particularly important because about half of patients with cardiovascular disease have obstructive sleep apnea. There was no indication of a reduction in cardiovascular risk with CPAP. However, there was evidence of some improvement in symptoms, which may lead some patients to try this treatment.