Whom are we treating with adaptive servo-ventilation? A clinical post hoc analysis

Background Recent evidence has shown that adaptive servo-ventilation (ASV) is contraindicated in patients with predominant central sleep apnea (CSA) and reduced left ventricular ejection fraction (LVEF <= 45%). The objective of this study was to assess the clinical usage of ASV in patients at the time-point of the release of a safety warning by type of SDB, breathing pattern and LVEF. Methods Patients of a cardiac and a respirology sleep center, both in Germany, who received ASV therapy were contacted between May and October 2015. Retrospective analyses included diagnostic polysomnography, polysomnography with continuous positive airway pressure prior to ASV initiation and echocardiography. Treatment emergent CSA was diagnosed after an appropriate treatment period on CPAP. Results 285 patients receiving ASV therapy (91 in the cardiac and 194 in the respirology setting) underwent diagnostic polysomnography. 233 (82%) patients had severe SDB, 94 (33%) predominant CSA, and 185 (65%) periodic breathing. 20% (n = 52) of patients had an LVEF of <= 45%. The most common indications for ASV were CSA in heart failure (41%) in the cardiac setting and treatment emergent CSA (80%) diagnosed after an appropriate period on CPAP in the respirology setting. The proportion of patients in whom ASV was contraindicated (CSA and LVEF <= 45%) was 16% in the cardiac setting and 9% in the respirology setting. Conclusion Clinical usage of ASV changed for a small subgroup of patients after release of the SERVE-HF results. Nevertheless, ASV treatment should be monitored and evaluated with diligence in the reminder indications

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 &lt; 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.</p