An interventional study of Active CPAP and Sham CPAP in Autonomic Failure, Pure Autonomic Failure and Multiple System Atrophy, sponsored by Vanderbilt University Medical Center. Recruiting at 1 site in United States. Open to participants aged 40 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-04-07.
Sponsored by Vanderbilt University Medical Center · Not applicable, Interventional, and Treatment
This study aims to learn about the effects of continuous positive airway pressure (CPAP) on people with autonomic failure and high blood pressure when lying down (supine hypertension) to determine if it can be used to treat their high blood pressure during the night. CPAP (a widely used treatment for sleep apnea) involves using a machine that blows air into a tube connected to a mask covering the nose, or nose and mouth, to apply a low air pressure in the airways.
The study includes 3-5 days spent in the Vanderbilt Clinical Research Center (CRC): at least one day of screening tests, followed by up to 3 study days. Subjects may be able to participate in daytime and/or overnight studies. The Daytime study consists of 2 study days: one with active CPAP and one with sham CPAP applied for up to 2 hours. The Overnight study consists of 3 study nights: one with active CPAP, one with sham CPAP, both applied for up to 9 hours and one night sleeping with the bed tilted head-up.
The study includes up to 5 days spent in the Vanderbilt University Medical Center, at least one day of screening tests, followed by 2 study days and/or 2 study nights.
Screening tests include a physical examination and history, routine safety laboratory assessments, and autonomic nervous system testing. Medications for high blood pressure will be held for at least 5 half-lives before studies. Subjects may be able to participate in the daytime and/or the overnight studies.
Daytime Study:
Eligible participants will be studied on two separate days in random order: one day with a high CPAP level and one day with a low CPAP level. The active CPAP level will be determined during a CPAP titration trial
On each study day, participants will be instrumented to measure blood pressure, heart rate, hemodynamic parameters, segmental impedance, and markers of cardiovascular risk. A saline lock or IV catheter will be inserted in one of the arm's veins for blood sample collection. Urine will also be collected during studies.
After baseline measurements, active or sham CPAP will then be applied for up to 2 hours. Outcome measurements will be repeated after 1 and 2 hours of CPAP.
Overnight Studies:
Eligible participants will be studied on three separate nights in random order with a active CPAP, sham CPAP, and sleeping in a head-up tilt position. The active CPAP level will be determined during a CPAP titration trial.
On each study night, the intervention (active CPAP, sham CPAP, or head-up tilt position) will be applied for up to 9 hours. Blood pressure, heart rate, hemodynamic parameters, and markers of cardiovascular risk will be assessed throughout the night. Urine will also be collected during this period. On the following morning, participants will have a tilt table test.
56 studies on the registry are indexed under Pure Autonomic Failure; 10 are open to participants now.
This study's planned enrollment of 59 is above the median of 39 across 41 interventional studies indexed under Pure Autonomic Failure.
Browse Pure Autonomic Failure studies →Vanderbilt University Medical Center is the lead sponsor of 833 studies on the registry; 155 are open to participants now.
Of its 125 completed or terminated interventional studies of FDA-regulated products, 92 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CPAP at 8, 10, or 12 cm H2O is applied for up to 2 hours while supine and awake.
Device: Active CPAP
Sham CPAP is applied for up to 2 hours while supine and awake.
Device: Sham CPAP
CPAP at 8, 10, or 12 cm H2O is applied for up to 9 hours during the night.
Device: Active CPAP
Sham CPAP is applied for up to 9 hours during the night.
Device: Sham CPAP
Sleeping with the bed tilted head-up by 10 degrees for up to 9 hours during the night.
Other: Sleeping in a head-up tilt (HUT) position
Continuous positive airway pressure (CPAP) is applied at 8, 10, or 12 cm H20. The active CPAP level will be determined during a CPAP titration trial
Also known as: Active continuous positive airway pressure
Sham continuous positive airway pressure applied at \<4 cm H2O
Also known as: Sham continuous positive airway pressure
Sleeping with the whole bed tilted head-up by 10 degrees or with the head elevated by 13-14 inches.
Also known as: HUT sleeping
Systolic blood pressure (daytime)
Change from baseline in systolic blood pressure at 2 hours of the intervention
Time frame: day 1 and 2 (within 2 hours of the intervention)
Systolic blood pressure (overnight)
Area under the curve of the change from baseline in systolic blood pressure
Time frame: up to 9 hours during the intervention
Stroke Volume (daytime)
Change from baseline in stroke volume at 1and 2 hours of the intervention
Time frame: day 1 and 2 (within 2 hours of the intervention)
Natriuretic hormone (daytime)
Percent change from baseline in N-terminal-proatrial natriuretic peptide at 2 hours after the intervention
Time frame: day 1 and 2 (within 2 hours of the intervention)
Nocturnal diuresis (overnight)
Urine volume collected during the night
Time frame: up to 9 hours during the intervention
Morning orthostatic tolerance (overnight)
Area under the curve of the upright systolic blood pressure during head-up tilt
Time frame: during 10 minutes upright tilt
Plan to share: No
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