HALOA: Cardiac Coherence With CPAP for Obstructive Sleep Apnea

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.

Participants will start HALOA CPAP at study inclusion. The cardiac coherence breathing module will be activated from the start of treatment, with guidance on its use. Participants will be assessed at baseline, week 8, and week 16.

Device: HALOA Continuous Positive Airway Pressure (CPAP) · Behavioral: Cardiac Coherence Breathing Module

Participants will start HALOA CPAP at study inclusion and use it without the cardiac coherence module for 8 weeks. After the week 8 assessment, the module will be activated and guidance on its use provided. Participants will be assessed at baseline, week 8, and week 16.

Device: HALOA Continuous Positive Airway Pressure (CPAP)

CPAP treatment using the HALOA system, initiated at study inclusion in both groups and provided as part of usual care.

Guided cardiac coherence breathing sessions using the module integrated with the HALOA system. The module is activated at study inclusion in the experimental group and after the week 8 assessment in the active comparator group.

Time frame: Baseline to week 8

Absolute change in the global PSQI score from baseline (V1) to week 8 (V2), comparing the randomized groups. PSQI scores range from 0 to 21; higher scores indicate poorer sleep quality.

Time frame: Week 8 to week 16

Absolute change in global PSQI score from week 8 (V2) to week 16 (V3) in the delayed-intervention group, after the cardiac coherence module is activated.

Time frame: Baseline, week 8, and week 16

Changes in Epworth Sleepiness Scale (ESS)

Time frame: Baseline, week 8, and week 16

Changes in Insomnia Severity Index (ISI)

Time frame: Baseline, week 8, and week 16

Changes in Hospital Anxiety and Depression Scale anxiety and depression subscale scores (HADS-A and HADS-D).

Time frame: Baseline, week 8, and week 16, as applicable

Patient satisfaction measured using the Client Satisfaction Questionnaire (CSQ-8) and the study-specific S-HALOA-CC questionnaire. S-HALOA-CC results will be considered exploratory.

Time frame: Week 8 for the immediate-intervention group and week 16 for the delayed-intervention group

Usability measured using the System Usability Scale (SUS) after exposure to the cardiac coherence module.

Time frame: At weeks 8 and 16; device use assessed over the 7-day and 30-day periods before each visit

Mean nightly CPAP use and the proportion of participants meeting the protocol-defined adherence threshold of at least 4 hours per night on at least 70% of nights.

Time frame: Baseline and week 16, when recordings are available

Changes in time-domain and frequency-domain heart-rate variability indices derived from polysomnography recordings, when follow-up recordings are available.

Time frame: Baseline to week 8, week 8 to week 16, and baseline to week 16

Proportion of participants with a decrease of at least 3 points in global PSQI score over the specified assessment interval.

Effect of Adding Cardiac Coherence to Continuous Positive Airway Pressure in Patients With Obstructive Sleep Apnea: A Multicenter Randomized Delayed-Start Controlled Study