High Altitude Pulmonary HypertensionNCT05089487
Nocturnal Oxygenation and Sleep-related Breathing Disorders During the First Night of a Stay at 2500m of High Altitude in Patients With Precapillary Pulmonary Hypertension
A study testing Nocturnal rest (sleep study) in people with High Altitude Pulmonary Hypertension and Sleep, run by University of Zurich at 1 site in Switzerland.
Trial summary
The impact of hypoxia at 2500m of high altitude on sleep in patients with precapillary pulmonary hypertension Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- High Altitude Pulmonary Hypertension, Sleep
- What is being tested?
- Nocturnal rest (sleep study)
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteSwitzerland
- Study dates
- 18 Oct 2021to 15 Apr 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Informed consent as documented by signature (Appendix Informed Consent Form)
- PH class I (PAH) or IV (CTEPH) diagnosed according to guidelines: mean pulmonary artery pressure >20 mmHg, pulmonary vascular resistance ≥3 wood units, pulmonary arterial wedge pressure ≤15 mmHg during baseline measures at the diagnostic right-heart catheterization
Who cannot join
- resting partial pressure of oxygen <8 kilopascal at Zurich at 490 m low altitude
- exposure to an altitude >1000 m for ≥3 nights during the last 2 weeks before the study
- inability to follow the procedures of the study
- other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Impact of Hypoxia on Patients With Precapillary Pulmonary Hypertension and Treatment of Adverse Effects
The impact of hypoxia at 2500m of high altitude on sleep in patients with precapillary pulmonary hypertension
- Conditions
- High Altitude Pulmonary Hypertension, Sleep
- Being tested
- Nocturnal rest (sleep study)
- Medical subject headings
- Pulmonary edema of mountaineers
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nocturnal rest (sleep study)Procedure or surgery
Proportion of patients free of severe hypoxemia without oxygen therapy during nocturnal rest .
| Study group | Role | What they receive |
|---|---|---|
| High altitude 2500 m above sea level | Experimental | Not described Receives: Procedure: Nocturnal rest (sleep study) |
| Low altitude 470 m above sea level | Active comparator | Not described Receives: Procedure: Nocturnal rest (sleep study) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportion of patients free of severe hypoxemia
Proportion of patients free of severe hypoxemia (defined as oxygenation (SpO2)<80% for >30 min) without oxygen therapy during nocturnal rest at 2500 m vs. 490 m
Measured: 30 hours
Secondary outcomes (13)
Nocturnal oxygenation
Difference in mean nocturnal oxygenation (SpO2) 2500 m of high altitude vs 490 m low altitude
Measured: 30 hours
Oxygen desaturation index
Difference in oxygen desaturation index sleeping at 2500 m high altitude vs 490 m low altitude
Measured: 30 hours
Periodic breathing
Difference in time spent with periodic breathing in patients sleeping at 2500 m of high altitude vs 490 m low altitude
Measured: 30 hours
Nocturnal transcutaneous carbon dioxide tension
Difference in nocturnal transcutaneous carbon dioxide tension in patients sleeping at 2500 m of high altitude vs 490 m low altitude
Measured: 30 hours
Visual Analogue Scale
Subjective sleep quality Visual Analogue Scale score 2500 m high altitude vs 490 m low altitude
Measured: 30 hours
Time spent awake during the night
Subjective time spent awake during the night high altitude vs 490 m low altitude
Measured: 30 hours
Cerebral tissue deoxygenation
Proportion of patients free of severe cerebral tissue deoxygenation (drop in cerebral tissue oxygen saturation >5%) without oxygen therapy during a night at 2500 vs. 490 m
Measured: 30 hours
Cerebral tissue oxygen saturation awake
Difference in cerebral tissue oxygen saturation awake in patients with precapillary pulmonary hypertension at 2500m of high altitude without supplemental oxygen vs. low altitude
Measured: 30 hours
Cerebral tissue oxygen saturation during sleep without oxygen
Difference in cerebral tissue oxygen saturation during sleep in patients with precapillary pulmonary hypertension at 2500m of high altitude without supplemental oxygen
Measured: 30 hours
Cerebral tissue oxygen saturation during sleep with oxygen
Difference in cerebral tissue oxygen saturation during sleep in patients with precapillary pulmonary hypertension at 2500m of high altitude with supplemental oxygen
Measured: 30 hours
Cerebral oxygen desaturation index without oxygen
Difference in the cerebral oxygen desaturation index in patients with precapillary pulmonary hypertension at 2500m of high altitude without supplemental oxygen vs. low altitude
Measured: 30 hours
Cerebral oxygen desaturation index with oxygen
Difference in the cerebral oxygen desaturation index in patients with precapillary pulmonary hypertension at 2500m of high altitude under supplemental oxygen.
Measured: 30 hours
Cerebral tissue oxygen saturation between different sleep stages
Changes in the cerebral tissue oxygen saturation between different sleep stages at 2500 m compared to low altitude.
Measured: 30 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Oct 2021
- Study start18 Oct 2021
- Primary completion15 Apr 2022
- Study completion15 Apr 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for High Altitude Pulmonary HypertensionStudies of the same condition, open and under way.
- More trials run by University of ZurichThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Screening
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 28 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05089487
- Sponsor's protocol ID
- OVERALP II E
- Status last verified
- May 2022
- First submitted
- 14 Oct 2021
- Last updated
- 11 May 2022
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Lichtblau M, Schwarz EI, Ulrich T, Schneider SR, Bauer M, Furian M, Carta A, Forrer A, Saxer S, Muller J, Preiss H, Mayer L, Bloch KE, Ulrich S. Effect of an Overnight Stay at 2,500 Meters on Nocturnal Hypoxemia and Sleep-disordered Breathing in Patients with Pulmonary Vascular Disease: A Randomized Clinical Trial. Ann Am Thorac Soc. 2025 Jul;22(7):1053-1061. doi: 10.1513/AnnalsATS.202412-1279OC.
PubMed 40085143
Study at a glance
From the registry record, last updated by the sponsor on 11 May 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Impact of Hypoxia on Patients With Precapillary Pulmonary Hypertension and Treatment of Adverse Effects
- ClinicalTrials.gov ID
- NCT05089487
- Acronym / sponsor ID
- OVERALP II E
- Conditions
- High Altitude Pulmonary Hypertension, Sleep
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 28 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Study start
- 18 Oct 2021 (actual)
- Primary completion
- 15 Apr 2022 (actual)
- Study completion
- 15 Apr 2022 (actual)
- First posted
- 22 Oct 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The impact of hypoxia at 2500m of high altitude on sleep in patients with precapillary pulmonary hypertension
Study design
- Primary purpose
- Screening
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| High altitude 2500 m above sea level | Experimental | Procedure: Nocturnal rest (sleep study) |
| Low altitude 470 m above sea level | Active comparator | Procedure: Nocturnal rest (sleep study) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Informed consent as documented by signature (Appendix Informed Consent Form)
- PH class I (PAH) or IV (CTEPH) diagnosed according to guidelines: mean pulmonary artery pressure >20 mmHg, pulmonary vascular resistance ≥3 wood units, pulmonary arterial wedge pressure ≤15 mmHg during baseline measures at the diagnostic right-heart catheterization
Key exclusion criteria (4 listed)
- resting partial pressure of oxygen <8 kilopascal at Zurich at 490 m low altitude
- exposure to an altitude >1000 m for ≥3 nights during the last 2 weeks before the study
- inability to follow the procedures of the study
- other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nocturnal rest (sleep study)Proportion of patients free of severe hypoxemia without oxygen therapy during nocturnal rest . | Procedure or surgery | High altitude 2500 m above sea level, Low altitude 470 m above sea level |
Primary outcome
Proportion of patients free of severe hypoxemia
Time frame: 30 hours
Proportion of patients free of severe hypoxemia (defined as oxygenation (SpO2)<80% for >30 min) without oxygen therapy during nocturnal rest at 2500 m vs. 490 m
13 secondary outcomes
Nocturnal oxygenation
Time frame: 30 hours
Oxygen desaturation index
Time frame: 30 hours
Periodic breathing
Time frame: 30 hours
Nocturnal transcutaneous carbon dioxide tension
Time frame: 30 hours
Visual Analogue Scale
Time frame: 30 hours
Time spent awake during the night
Time frame: 30 hours
Cerebral tissue deoxygenation
Time frame: 30 hours
Cerebral tissue oxygen saturation awake
Time frame: 30 hours
Cerebral tissue oxygen saturation during sleep without oxygen
Time frame: 30 hours
Cerebral tissue oxygen saturation during sleep with oxygen
Time frame: 30 hours
Cerebral oxygen desaturation index without oxygen
Time frame: 30 hours
Cerebral oxygen desaturation index with oxygen
Time frame: 30 hours
Cerebral tissue oxygen saturation between different sleep stages
Time frame: 30 hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 May 2022.
- Derived from this study: PubMed 40085143Lichtblau M, Schwarz EI, Ulrich T, Schneider SR, Bauer M, Furian M, Carta A, Forrer A, Saxer S, Muller J, Preiss H, Mayer L, Bloch KE, Ulrich S. Effect of an Overnight Stay at 2,500 Meters on Nocturnal Hypoxemia and Sleep-disordered Breathing in Patients with Pulmonary Vascular Disease: A Randomized Clinical Trial. Ann Am Thorac Soc. 2025 Jul;22(7):1053-1061. doi: 10.1513/AnnalsATS.202412-1279OC.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nocturnal rest (sleep study) in people with High Altitude Pulmonary Hypertension and Sleep, run by University of Zurich at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 May 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportion of patients free of severe hypoxemia (time frame: 30 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05089487, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 May 2022.