What Can Improve Outcomes in Patients With Comorbid OSA, HFrEF?

Automatic positive airway pressure (APAP) was found to significantly improve peak oxygen uptake (VO₂), left ventricular function, and quality of life in patients with comorbid obstructive sleep apnea (OSA) and heart failure with reduced left ventricular ejection fraction (HFrEF), according to study findings published in Clinical Research in Cardiology.

As researchers highlight, moderate-to-severe OSA serves as a highly prevalent comorbidity in patients with HFrEF. In fact, epidemiological studies have identified OSA as an independent risk factor of heart failure, as well as a negative factor on prognosis that can lead to worsening cardiac function and increased risk of mortality.

While patients with heart failure are expected to benefit from APAP, which promotes cardiac filling pressures and notably, right ventricular function, a prior study found no significant benefits on the rate of cardiovascular events and mortality. However, researchers note that the study’s APAP duration use was lower (3.3 hours per night) than what is typically associated with achieving measurable benefits (minimum 4 hours per night).

Researchers sought to further assess the impact of APAP therapy in patients with HFrEF by examining primary endpoints peak VO₂ , percent-predicted peak VO₂, and oxygen uptake at anaerobic threshold (VO₂—AT) during a cardiopulmonary exercise test. The study randomized 76 patients with chronic, stable HFrEF who had moderate-to-severe OSA at a ratio of 1:1 to receive APAP or nasal strips (control) for 6 months.

After evaluating data from the 2 patient groups, 58 had complete information for the final analysis. Based on study findings, a significant change was observed in the primary endpoint of percent-predicted peak VO₂ for the intervention group compared with the control (6.58%; P = .01). The primary endpoint of peak VO₂ was improved for the intervention group compared with the control (1.15 mL/kg/ min higher), but the between-group difference was not statistically significant.

Findings also indicated significant improvements in the intervention group for hypoxemia (P = .001), left ventricular function (P = .001), and quality of life (P = .037) from baseline to 6 months that were not found in the control group.

“More data, long-term and larger studies are needed to determine the impact of our findings on heart failure outcome, including mortality,” concluded the study authors.

Reference

Fox H, Bitter T, Sauzet O, et al. Automatic positive airway pressure for obstructive sleep apnea in heart failure with reduced ejection fraction. Clin Res Cardiol. Published online July 10, 2020. doi:10.1007/s00392-020-01701-1