Moderate-to-severe obstructive sleep apnea (OSA) is highly prevalent in heart failure patients with reduced left ventricular ejection fraction (HFrEF), and is associated with worsening cardiac function and increased mortality.
The automatic positive airway pressure (APAP) trial tested the impact of APAP treatment on changes for the pre-specified endpoints: changes in peak oxygen uptake (peak VO), percent-predicted peak VO and oxygen uptake at anaerobic threshold (VO-AT).
This randomized, controlled pilot study included patients with chronic, stable HFrEF who had moderate-to-severe OSA. Patients were randomized 1:1 to either APAP (AutoSet™, ResMed) or nasal strips (control) for 6 months.
76 patients have been randomized and 58 had complete data for final analysis. There was a statistically significant change in the APAP intervention arm for the primary endpoint percent-predicted peak VO in comparison to control (67 ± 17 to 73 ± 19%; p = 0.01). Additional primary endpoints peak VO and VO-AT showed a trend in increase in the APAP group. Moreover, there were significant improvements within the APAP group for hypoxemia, left ventricular function and quality of life from baseline to 6 months, but not within the control group (p = 0.001 and p = 0.037, respectively).
APAP intervention was shown to significantly improve outcome compared to control group, represented in percent-predicted peak VO, an established surrogate marker for cardiovascular prognosis in HFrEF. APAP has additional beneficial effects on hypoxemia, cardiac function and quality of life.