Prospective Evaluation of New Metrics to Assess Cardiovascular Remodeling in Obstructive Sleep Apnea (CARDOSA)

The goal of this prospective study is to gain insight into the endophenotypic variation in OSA, with a focus on the underlying pathophysiological traits and the cardiovascular alterations associated with the condition. To capture the variability in OSA endophenotypes, novel metrics that extend beyond the AHI will be considered, with particular attention to the sleep-apnea-specific hypoxic burden, the sleep-apnea-specific heart rate response, and pulse wave amplitude drops (PWADs). Since the impact of treatment on cardiovascular parameters remains an important point of interest, the effects of different treatment modalities on cardiovascular changes will be investigated, including continuous positive airway pressure (CPAP), mandibular advancement devices (MADs), and hypoglossal nerve stimulation.

Study Overview

• Status: Not yet recruiting
• Conditions: Obstructive Sleep Apnea; Cardiovascular (CV) Risk
• Intervention / Treatment: Device: Continuous positive airway pressure; Device: Mandibular advancement device; Device: Hypoglossal nerve stimulation

• Study Type: Observational
• Enrollment (Estimated): 270

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of patients diagnosed with moderate to severe obstructive sleep apnea (OSA) (AHI≥15/h), recruited by the OSA multidisciplinary team.

Description

Inclusion Criteria:

• AHI ≥ 15 events/hour, based on a recent (<2 years) PSG
• Patients must be18 years or older
• Patients must be eligible for their chosen therapy (CPAP, MAD or HNS)
• Willing to participate after informed consent

Exclusion Criteria:

• Central apneas accounting for ≥25% of total apneas during baseline polysomnography.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep apnea-specific hypoxic burden (SASHB)	This novel metric is calculated by determining the total area under the respiratory event-related desaturation curve, which can be obtained from a polysomnography (PSG). It has been shown to be a good predictor of cardiovascular disease mortality, but has not yet been established in daily practice.	1 year
Cardiovascular outcome: interventricular septum thickness	Interventricular septal thickness will be assessed via 2D-guided M-mode echocardiographic measurements in the parasternal long-axis view.	1 year
Cardiovascular outcome: left ventricular ejection fraction	Left ventricular ejection fraction will be assessed via 2D-guided M-mode echocardiographic measurements in the parasternal long-axis view.	1 year
Cardiovascular outcome: heart rate variability	Heart rate variability will be calculated from ECG-derived RR intervals obtained during the sleep study.	1 year
OSA efficacy: delta apnea-hypopnea index (AHI)	The apnea-hypopnea Index (AHI), defined as the number of apneas (cessations in breathing) and hypopneas (reductions in airflow) per hour of sleep measured during a polysomnography, will be assessed. OSA is diagnosed when the AHI is at least 5/h. The AHI classifies OSA as mild with AHI ranging from 5 to 14.9 events per hour, moderate with AHI ranging from 15 to 29.9 events per hour and severe when 30 or higher events per hour.	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate response to a respiratory event (ΔHR)	ΔHR is defined as the difference between the maximum pulse rate after airway opening, i.e. during a subject-specific search window, and an event-related minimum pulse rate, i.e. minimum pulse rate during respiratory events. ΔHR will be calculated from a photoplethysmography (PPG), a signal derived from a finger pulse oximeter, which is part of the standard clinical PSG set-up.	1 year
Pulse wave amplitude drops (PWADs)	PWADs can be calculated from photoplethysmography (PPG), a signal derived from a finger pulse oximeter, which is part of the standard clinical PSG set-up.	1 year
Cardiovascular outcome: 24-hour ambulatory blood pressure	24-hour ambulatory blood pressure will be measured using ambulatory blood pressure monitoring (ABPM).	1 year
Cardiovascular outcome: systolic and diastolic function	Left ventricular systolic and diastolic function will be evaluated using 2D echocardiography. Systolic function will be quantified by left ventricular ejection fraction calculated using the Simpson biplane method. Diastolic function will be assessed using pulsed wave tissue Doppler imaging at the septal and lateral mitral annulus, mitral inflow velocities (E/A ratio), the E/e' ratio and left atrial volume index.	1 year
Therapy adherence defined by the amount of hours of therapy usage per night and the number of nights per week of use	Average hours of therapy use per night and the number of nights per week can be retrieved from data stored in the device.	1 year
Degree of snoring measured by Visual Analogue Scale (VAS)	Visual analogue scale for snoring, from 0 to 10: 0 represents no snoring, 1-3 represents minimally annoying, 4-6 represents moderately annoying, 7-9 represents annoying, and 10 represents extremely annoying.	1 year
Daytime sleepiness measured by the Epworth Sleepiness Scale (ESS) questionnaire	Daytime sleepiness measured using the Epworth sleepiness scale (ESS), which is a self-administered questionnaire that assesses the likelihood of falling asleep in various settings and situations in daily life.The questionnaire consists of eight items scored from 0 to 3, resulting in a total score ranging from 0 to 24. The lowest score (zero) suggests that the described incident is absent and the highest score (three) suggests the presence of this event.	1 year
Fatigue measured by the Checklist Individual Strength (CIS) questionnaire	Fatigue was assessed using the checklist individual strength, a 20-item questionnaire with each item scored on a 7-point Likert scale, resulting in total scores ranging from 20 to 140. Higher scores indicate greater fatigue severity.	1 year

Collaborators and Investigators

• Sponsor: University Hospital, Antwerp

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2029

Study Registration Dates

• First Submitted: January 30, 2026
• First Submitted That Met QC Criteria: February 20, 2026
• First Posted (Actual): February 23, 2026

Study Record Updates

• Last Update Posted (Actual): February 23, 2026
• Last Update Submitted That Met QC Criteria: February 20, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Respiratory Tract Diseases; Respiration Disorders; Sleep Wake Disorders; Apnea; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Therapeutics; Orthopedic Equipment; Surgical Equipment; Equipment and Supplies; Airway Management; Respiratory Therapy; Positive-Pressure Respiration; Respiration, Artificial; Orthotic Devices; Continuous Positive Airway Pressure; Occlusal Splints
• Other Study ID Numbers: 4699; G063725N (Other Identifier: FWO)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No