HALOA: Cardiac Coherence With CPAP for Obstructive Sleep Apnea (HALOA)

Obstructive sleep apnea is commonly treated with continuous positive airway pressure (CPAP). However, some patients have difficulty adhering to CPAP or experience persistent sleep-related symptoms. Cardiac coherence is a guided breathing practice intended to support relaxation and emotional regulation. The HALOA system combines CPAP treatment with a cardiac coherence module. This study will assess whether access to this module from the start of CPAP treatment improves subjective sleep quality compared with starting the module after an initial period of CPAP alone.

This is a prospective, multicenter, randomized, open-label, delayed-start controlled study. Approximately 180 adults with newly diagnosed obstructive sleep apnea and an indication for CPAP will be enrolled at 11 planned centers. Participants will be randomly assigned in equal numbers to one of two groups.

All participants will begin CPAP treatment using the HALOA system and will receive usual CPAP care. Participants in the immediate-intervention group will have the cardiac coherence module activated at study entry and will receive guidance on its use. Participants in the delayed-intervention group will use CPAP without cardiac coherence for the first 8 weeks. After the week 8 assessment, the module will be activated and participants will receive guidance on its use.

Study assessments will take place at baseline, week 8, and week 16. The primary outcome is the change in the global Pittsburgh Sleep Quality Index (PSQI) score from baseline to week 8, comparing the two randomized groups. The week 8 assessment provides the controlled comparison before participants in the delayed-intervention group begin cardiac coherence. Changes in PSQI from week 8 to week 16 in the delayed-intervention group will also be assessed to explore the effect after the module is introduced.

Secondary assessments will include daytime sleepiness using the Epworth Sleepiness Scale, insomnia symptoms using the Insomnia Severity Index, and anxiety and depression symptoms using the Hospital Anxiety and Depression Scale. Patient satisfaction will be assessed using the CSQ-8 and a study-specific questionnaire. Usability of the cardiac coherence module will be assessed using the System Usability Scale. CPAP adherence will be evaluated using device data, including hours of use and the proportion of participants meeting the protocol-defined adherence threshold. Heart-rate variability indices will be evaluated from polysomnography recordings when available.

Participants will be adults with obstructive sleep apnea diagnosed by polysomnography within the 3 months before inclusion and for whom CPAP treatment is indicated. The protocol lists recent CPAP or mandibular advancement device treatment, refusal of or contraindication to CPAP, inability to use the cardiac coherence device, and specified medical, psychiatric, or other circumstances among the non-inclusion criteria.