Central sleep apnea is frequently observed in patients suffering from heart failure and is associated with a poorer prognosis. Adaptive servo-ventilation (ASV) is a therapy employed to manage central sleep apnea. This noninvasive ventilation method delivers servo-controlled inspiratory pressure support in addition to expiratory positive airway pressure. A study was conducted to evaluate the effectiveness of adaptive servo-ventilation in patients with heart failure with reduced ejection fraction who also presented with predominantly central sleep apnea.
In a randomized controlled trial, 1325 patients with a left ventricular ejection fraction of 45% or less and an apnea-hypopnea index (AHI) of 15 or more events per hour, characterized by a predominance of central events, were enrolled. Participants were randomly assigned to receive guideline-based medical treatment combined with adaptive servo-ventilation or guideline-based medical treatment alone (control group). The primary endpoint was defined as the first occurrence of death from any cause, a lifesaving cardiovascular intervention (including cardiac transplantation, ventricular assist device implantation, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock), or unplanned hospitalization due to worsening heart failure. This endpoint was analyzed using a time-to-event approach.
The results indicated that in the adaptive servo-ventilation group, the mean AHI at 12 months significantly decreased to 6.6 events per hour, demonstrating the therapy’s effectiveness in treating sleep apnea. However, the study found no significant difference in the incidence of the primary endpoint between the adaptive servo-ventilation group and the control group. Specifically, the primary endpoint occurred in 54.1% of patients in the ASV group and 50.8% in the control group (hazard ratio, 1.13; 95% confidence interval [CI], 0.97 to 1.31; P=0.10). More concerningly, the study revealed that all-cause mortality and cardiovascular mortality were significantly higher in the adaptive servo-ventilation group compared to the control group. The hazard ratio for death from any cause was 1.28 (95% CI, 1.06 to 1.55; P=0.01), and the hazard ratio for cardiovascular death was 1.34 (95% CI, 1.09 to 1.65; P=0.006).
The study concluded that adaptive servo-ventilation, while effective in treating central sleep apnea, did not show a beneficial effect on the composite primary endpoint in patients with heart failure and reduced ejection fraction. Furthermore, the therapy was associated with an increased risk of both all-cause and cardiovascular mortality in this patient population. These findings suggest that adaptive servo-ventilation should be used with caution in patients with heart failure and predominantly central sleep apnea due to the potential for adverse outcomes, particularly increased mortality. The research was funded by ResMed and other sources, and the study is registered at ClinicalTrials.gov under the identifier NCT00733343 (SERVE-HF).
