Adaptive servo-ventilation in cardiac function and neurohormonal status in patients with heart failure and central sleep apnea nonresponsive to continuous positive airway pressure.

OBJECTIVES The aim of this study was to investigate whether effective suppression of central sleep apnea (CSA) by adaptive servo-ventilation (ASV) improves underlying cardiac dysfunction among patients with heart failure (HF) in whom CSA was not effectively suppressed by continuous positive airway pressure (CPAP). BACKGROUND The presence of CSA in HF is associated with a poor prognosis, whereas CPAP treatment improves HF. However, in a large-scale trial, CPAP failed to improve survival, probably due to insufficient CSA suppression. Recently, ASV was reported as the most effective alternative to CSA suppression. However, the effects of sufficient CSA suppression by ASV on cardiac function are unknown. METHODS Patients with New York Heart Association class ≥II HF, left ventricular ejection fraction <50%, and CSA that was unsuppressed (defined as an apnea-hypopnea index ≥15) despite ≥3 months of CPAP were randomly assigned to receive ASV in either CPAP mode or ASV mode. RESULTS Of 23 patients enrolled, 12 were assigned to the ASV-mode group and 11 were assigned to the CPAP-mode group. Three months after randomization, the ASV mode was significantly more effective in suppressing the apnea-hypopnea index (from 25.0 ± 6.9 events/h to 2.0 ± 1.4 events/h; p < 0.001) compared to the CPAP mode. Compliance was signi-ficantly greater with the ASV mode than with the CPAP mode. Improvement in left ventricular ejection fraction was greater with the ASV mode (32.0 ± 7.9% to 37.8 ± 9.1%; p < 0.001) than with the CPAP mode. CONCLUSIONS Patients with HF and unsuppressed CSA despite receiving CPAP may receive additional benefit by having CPAP replaced with ASV. Additionally, effective suppression of CSA may improve cardiac function in HF patients.