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.

Automated summary

ASV treatment reduced AHI in all patient groups, but nocturnal hypoxemic burden remained high due to a non-specific component of T90 not related to episodic desaturation. Further study is warranted to explore whether adjunct risk factor management, such as weight-loss, can further reduce T90.