Registry on the Treatment of Central and Complex Sleep-Disordered Breathing with Adaptive Servo-Ventilation (READ-ASV): protocol and cohort profile.

Background: Although adaptive servo-ventilation (ASV) effectively supresses central sleep apnoea (CSA), little is known about real-world indications of ASV therapy and its effects on quality of life (QoL).

Methods: This report details the design, baseline characteristics, indications for ASV and symptom burden in patients enrolled in the Registry on the Treatment of Central and Complex Sleep-Disordered Breathing with Adaptive Servo-Ventilation (READ-ASV). This multicentre, European, non-interventional trial enrolled participants prescribed ASV in clinical practice between September 2017 and March 2021. An expert review board assigned participants to ASV indications using a guideline-based semi-automated algorithm. The primary end-point was change in disease-specific QoL based on the Functional Outcomes of Sleep Questionnaire (FOSQ) from baseline to 12-month follow-up.

Results: The registry population includes 801 participants (age 67±12 years, 14% female). Indications for ASV were treatment-emergent or persistent CSA (56%), CSA in cardiovascular disease (31%), unclassified CSA (2%), coexisting obstructive sleep apnoea and CSA (4%), obstructive sleep apnoea (3%), CSA in stroke (2%) and opioid-induced CSA (1%). Baseline mean apnoea--hypopnoea index was 48±23 events·h (≥30 events·h in 78%), FOSQ score was 16.7±3.0 (<17.9 in 54%) and Epworth Sleepiness Scale (ESS) score was 8.8±4.9 (>10 in 34%); 62% of patients were symptomatic (FOSQ score <17.9 or ESS score >10).

Conclusion: The most common indications for ASV were treatment-emergent or persistent CSA or CSA in cardiovascular disease (excluding systolic heart failure). Patients using ASV in clinical practice had severe sleep-disordered breathing and were often symptomatic. One-year follow-up will provide data on the effects of ASV on QoL, respiratory parameters and clinical outcomes in these patients.