CPAP Therapy and Atrial Fibrillation Recurrence in OSA (CPAP-AF)

January 14, 2026 updated by: Petar Rosenov Kalaydzhiev, Medical University of Sofia

Effects of CPAP Therapy on Atrial Fibrillation Recurrence in Patients With Obstructive Sleep Apnea: A Prospective Cohort Study

Obstructive sleep apnea (OSA) is a major modifiable risk factor for atrial fibrillation (AF). Continuous positive airway pressure (CPAP) therapy has been shown to improve cardiovascular outcomes; however, real-world data on its effect on AF recurrence remain limited.

This prospective cohort study aims to evaluate the association between objective CPAP adherence and the risk of AF recurrence in patients with moderate-to-severe OSA and a history of paroxysmal AF.

Patients will be followed for 12 months, with AF recurrence assessed using electrocardiography and Holter monitoring.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a prospective, real-world cohort study enrolling adult patients with moderate-to-severe obstructive sleep apnea (AHI ≥ 15 events/hour) and documented paroxysmal atrial fibrillation. OSA is diagnosed using home sleep apnea testing.

All participants initiate CPAP therapy, with objective adherence data collected via telemonitoring. Patients are followed for 12 months to assess AF recurrence, progression to permanent AF, and associations with CPAP usage metrics.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
91

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Bulgaria
      • Sofia, Bulgaria, 1000
        • UMHAT "Tcaritca Joanna - ISUL"

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients diagnosed with moderate-to-severe obstructive sleep apnea and a history of paroxysmal atrial fibrillation, managed in outpatient and hospital settings, and treated with continuous positive airway pressure therapy as part of routine clinical care.

Description

Inclusion Criteria:

  1. Age ≥ 18 years
  2. Diagnosed moderate-to-severe OSA
  3. History of paroxysmal atrial fibrillation
  4. Ability to initiate CPAP therapy
  5. Written informed consent -

Exclusion Criteria:

  1. Left ventricular ejection fraction < 50%
  2. Permanent atrial fibrillation
  3. Central sleep apnea
  4. End-stage chronic kidney disease
  5. Inability to obtain or tolerate CPAP therapy -

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
High CPAP adherence (≥ 4 h/night)
Participants with mean nightly CPAP use ≥ 4 hours.
Device: Continuous Positive Airway Pressure (CPAP)
CPAP therapy is initiated according to standard clinical practice. Objective adherence data (mean nightly usage, percentage of nights ≥ 4 hours) are collected via telemonitoring systems.
Low CPAP adherence (< 4 h/night)
Participants with mean nightly CPAP use < 4 hours.
Device: Continuous Positive Airway Pressure (CPAP)
CPAP therapy is initiated according to standard clinical practice. Objective adherence data (mean nightly usage, percentage of nights ≥ 4 hours) are collected via telemonitoring systems.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Time to First Recurrence of Paroxysmal Atrial Fibrillation
Time Frame: 12 months
First documented recurrence of paroxysmal AF confirmed by 12-lead ECG or 24-hour Holter monitoring.
12 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Progression to Permanent Atrial Fibrillation
Time Frame: 12 months
Progression to Permanent Atrial Fibrillation for 12 months
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Medical University of Sofia

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Petar R Kalaydzhiev, PhD, Medical University - Sofia

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 30, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 14, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 14, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 22, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • MP18/09.08.2024

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to data protection regulations and the absence of explicit participant consent for data sharing beyond the scope of the current study.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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