Nocturnal hypoxemic burden during positive airway pressure treatment across different central sleep apnea etiologies

Introduction: Nocturnal hypoxemia is associated with increased cardiovascular mortality. Here, we assess whether positive airway pressure by adaptive servo-ventilation (ASV) reduces nocturnal hypoxemic burden in patients with primary central sleep apnea (primary CSA), or heart failure related central sleep apnea (CSA-HF) and treatment emergent central sleep apnea (TECSA).

Methods: Overnight oximetry data from 328 consecutive patients who underwent ASV initiation between March 2010 and May 2018 were retrospectively analyzed. Patients were stratified into three groups: primary CSA (n = 14), CSA-HF (n = 31), TECSA (n = 129). Apnea hypopnea index (AHI) and time spent below 90% SpO(2) (T90) was measured. Additionally, T90 due to acute episodic desaturations (T90(Desaturation)) and due to non-specific and non-cyclic drifts of SpO(2) (T90(Non-specific)) were assessed.

Results: ASV reduced the AHI below 15/h in all groups. ASV treatment significantly shortened T90 in all three etiologies to a similar extent. T90(Desaturation), but not T90(Non-specific), was reduced by ASV across all three patient groups. AHI was identified as an independent modulator for Delta T90(Desaturation) upon ASV treatment (B (95% CI: -1.32 (-1.73; -0.91), p < 0.001), but not for Delta T90 or Delta T90(Non-specific). Body mass index was one independent predictor of T90.

Conclusions: Across different central sleep apnea etiologies, ASV reduced AHI, but nocturnal hypoxemic burden remained high due to a non-specific component of T90 not related to episodic desaturation. Whether adjunct risk factor management such as weight-loss can further reduce T90 warrants further study. (C) 2021 Elsevier B.V. All rights reserved.