Pulmonary Arterial Hypertension (PAH)NCT07804576
Assessment of Lung Function (Lufu) at Sea Level LA vs. High Altitude HA in Patients With Pulmonary Arterial Hypertension PAH
A study testing Re-ascent from sea level to 2850m in people with Pulmonary Arterial Hypertension (PAH) and Pulmonary Vascular Disease, run by Silvia Ulrich Somaini at 1 site in Switzerland.
Trial summary
To study the effect of a re-ascent to high altitude (Quito Ecuador: 2850m) after a one-week stay at sea level (after prior descent from 2850m) on lung function and pulmonary resistance/reactance in patients with pulmonary arterial disease PAH, who live permanently > 2600m. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease, High Altitude Effects
- What is being tested?
- Re-ascent from sea level to 2850m
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteSwitzerland
- Study dates
- 25 Sep 2026to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adult patients aged 18-80 years and of all genders
- Permanent residence > 2600 m
- Diagnosis of pulmonary arterial hypertension PAH (PAHHA-Group) according to guidelines
- Patients are stable on therapy
- NYHA (new york heart association) functional class I-III.
- written informed consent to participate in the study.
Who cannot join
- Age <18 years or >80 years
- unstable condition
- Patients who cannot follow the study investigations
- Patient permanently living < 2600m.
- Patients who traveled and stayed overnight at altitudes <2000 m in the past 4 weeks.
- Patients with moderate to severe concomitant lung disease (FEV1<70% or forced vital capacity <70%), severe parenchymal lung disease, severe smokers (>20 cigarettes/day)
Show all 9Show fewer
- Severely hypoxemic patients at Quito permanently having persistent SpO2 (oxygen saturation by pulseoximetry) <80% on ambient air.
- Patient with a non-corrected ventricular septum defect
- Relevant concomitant other disease of the heart, kidney, liver, blood (anemia hemoglobin<11 g/dl)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Michael Furian, Prof. Dr. sc. ETH contact
About this study
Official title: Effect of a One-week Descent From 2850m to Sea Level and Re-ascent in Patients With Pulmonary Arterial Hypertension and Healthy Controls Permanently Living > 2600m on Pulmonary Hemodynamics, Exercise Capacity, Blood Oxygenation, Sleep Disordered Breathing and Further Outcomes
To study the effect of a re-ascent to high altitude (Quito Ecuador: 2850m) after a one-week stay at sea level (after prior descent from 2850m) on lung function and pulmonary resistance/reactance in patients with pulmonary arterial disease PAH, who live permanently > 2600m.
Read the detailed description
The aim of this research is to investigate the lung function and pulmonary resistance/reactance before and after re-ascent (sea level for 7 days after prior descent from 2850m vs. re-ascent to 2850m) in patients with diagnosed pulmonary hypertension according to guidelines, who permanently live at high altitude over 2600m.
- Conditions
- Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease, High Altitude Effects, High Altitude, Lung Function Testing, Lung Function Changes
- Being tested
- Re-ascent from sea level to 2850m
- Keywords
- Pulmonary arterial hypertension PAH, Pulmonary vascular disease, High Altitude, Lung function, forced oscillation technique
- Medical subject headings
- Pulmonary Arterial Hypertension, Altitude Sickness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Re-ascent from sea level to 2850mBehavioural
Descent from 2850m to sea level with a stay for 7 days and re-ascent/return back to their usual living altitude at 2850m
| Study group | Role | What they receive |
|---|---|---|
| Lung function at sea level and at 2850m | Experimental | Assessment of lung function and pulmonary resistance/reactance on day four at sea level (after prior descent from 2850m) and after re-ascent (after totally one week at sea level) back to 2850m by bus (in one day) Receives: Behavioral: Re-ascent from sea level to 2850m |
What is being measured
The primary outcome is the main question the study is designed to answer.
FEV1 after re-ascent to 2850m
Difference/change in forced expiratory volume in one second FEV1 between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
Measured: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Secondary outcomes (17)
Forced Vital Capacity FVC after re-ascent to 2850m
Difference/change in forced vital capacity FVC between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
Measured: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
FEV1/FVC after re-ascent to 2850m
Difference/change in FEV1/FVC between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
Measured: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Respiratory Impedance (forced oscillation technique) after re-ascent to 2850m
Difference/change in respiratory impedance (forced oscillation technique) between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
Measured: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Respiratory resistance (forced oscillation technique) after re-ascent to 2850m
Difference/change in respiratory resistance (forced oscillation technique) between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
Measured: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Respiratory reactance (forced oscillation technique) after re-ascent to 2850m
Difference/change in respiratory reactance (forced oscillation technique) between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
Measured: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
FEV1 after 4 days at sea level
Difference/change in FEV1 between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
Measured: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Forced Vital Capacity FVC after 4 days at sea level
Difference/change in forced vital capacity FVC between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
Measured: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
FEV1/FVC after 4 days at sea level
Difference/change in FEV1/FVC between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
Measured: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Respiratory Impedance (forced oscillation technique) after 4 days at sea level
Difference/change in respiratory impedance (forced oscillation technique) between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
Measured: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Respiratory resistance (forced oscillation technique) after 4 days at sea level
Difference/change in respiratory resistance (forced oscillation technique) between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
Measured: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Respiratory reactance (forced oscillation technique) after 4 days at sea level
Difference/change in respiratory reactance (forced oscillation technique) between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
Measured: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
FEV1 pre-descent and after re-ascent (2850m)
Difference/change in FEV1 at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in patients with pulmonary arterial disease
Measured: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Forced Vital Capacity FVC pre-descent and after re-ascent (2850m)
Difference/change in forced vital capacity FVC at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in patients with pulmonary arterial hypertension
Measured: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
FEV1/FVC pre-descent and after re-ascent (2850m)
Difference/change in FEV1/FVC at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in patients with pulmonary arterial hypertension
Measured: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory Impedance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Difference/change in respiratory impedance (forced oscillation technique) at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in patients with pulmonary arterial hypertension
Measured: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory resistance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Difference/change in respiratory resistance (forced oscillation technique) at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in patients with pulmonary arterial hypertension
Measured: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory reactance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Difference/change in respiratory reactance (forced oscillation technique) at 2850m with a one-week stay at sea level in between (day pre-descent vs. day after re-ascent) in patients with pulmonary arterial hypertension
Measured: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Sep 2026
- Study start25 Sep 2026 (estimated)
- Primary completion4 Oct 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pulmonary Arterial Hypertension (PAH)Studies of the same condition, open and under way.
- 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
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Patients with pulmonary arterial hypertension living permanently \> 2600m around Quito (Ecuador) will be assessed at 2850m, after relocation to sea level for 7 days and after re-ascent
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Silvia Ulrich Somaini
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Silvia Ulrich Somaini, University of Zurich
- Investigators
- Silvia Ulrich, Principal investigator, University Hospital Zurich, Departement of PulmonologyRodrigo Hoyos, Principal investigator, Hospital Carlos Andrade Marin of Quito, Ecuador
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07804576
- Sponsor's protocol ID
- Ec_LAvsHA_Lufu_PAH
- Status last verified
- Aug 2026
- First submitted
- 17 Aug 2026
- Last updated
- 4 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data will be provided upon request and based on a clear intention reviewed by an ethical review board.
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of a One-week Descent From 2850m to Sea Level and Re-ascent in Patients With Pulmonary Arterial Hypertension and Healthy Controls Permanently Living > 2600m on Pulmonary Hemodynamics, Exercise Capacity, Blood Oxygenation, Sleep Disordered Breathing and Further Outcomes
- ClinicalTrials.gov ID
- NCT07804576
- Acronym / sponsor ID
- Ec_LAvsHA_Lufu_PAH
- Conditions
- Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease, High Altitude Effects, High Altitude, Lung Function Testing, Lung Function Changes
- Keywords
- Pulmonary arterial hypertension PAH, Pulmonary vascular disease, High Altitude, Lung function, forced oscillation technique
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Silvia Ulrich SomainiUniversity, hospital or other
- Study start
- 25 Sep 2026 (estimated)
- Primary completion
- 4 Oct 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 4 Sep 2026 (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.
To study the effect of a re-ascent to high altitude (Quito Ecuador: 2850m) after a one-week stay at sea level (after prior descent from 2850m) on lung function and pulmonary resistance/reactance in patients with pulmonary arterial disease PAH, who live permanently > 2600m.
Detailed description
The aim of this research is to investigate the lung function and pulmonary resistance/reactance before and after re-ascent (sea level for 7 days after prior descent from 2850m vs. re-ascent to 2850m) in patients with diagnosed pulmonary hypertension according to guidelines, who permanently live at high altitude over 2600m.
Study design
- Primary purpose
- Supportive care
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Patients with pulmonary arterial hypertension living permanently > 2600m around Quito (Ecuador) will be assessed at 2850m, after relocation to sea level for 7 days and after re-ascent
| Arm | Type | Receives |
|---|---|---|
| Lung function at sea level and at 2850m | Experimental | Behavioral: Re-ascent from sea level to 2850mAssessment of lung function and pulmonary resistance/reactance on day four at sea level (after prior descent from 2850m) and after re-ascent (after totally one week at sea level) back to 2850m by bus (in one day) |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adult patients aged 18-80 years and of all genders
- Permanent residence > 2600 m
- Diagnosis of pulmonary arterial hypertension PAH (PAHHA-Group) according to guidelines
- Patients are stable on therapy
- NYHA (new york heart association) functional class I-III.
Key exclusion criteria (9 listed)
- Age <18 years or >80 years
- unstable condition
- Patients who cannot follow the study investigations
- Patient permanently living < 2600m.
- Patients who traveled and stayed overnight at altitudes <2000 m in the past 4 weeks.
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 |
|---|---|---|
| Re-ascent from sea level to 2850mDescent from 2850m to sea level with a stay for 7 days and re-ascent/return back to their usual living altitude at 2850m | Behavioural | Lung function at sea level and at 2850m |
Primary outcome
FEV1 after re-ascent to 2850m
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Difference/change in forced expiratory volume in one second FEV1 between sea level (measurement on the 4th day) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension
17 secondary outcomes
Forced Vital Capacity FVC after re-ascent to 2850m
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
FEV1/FVC after re-ascent to 2850m
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Respiratory Impedance (forced oscillation technique) after re-ascent to 2850m
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Respiratory resistance (forced oscillation technique) after re-ascent to 2850m
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
Respiratory reactance (forced oscillation technique) after re-ascent to 2850m
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
FEV1 after 4 days at sea level
Time frame: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Forced Vital Capacity FVC after 4 days at sea level
Time frame: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
FEV1/FVC after 4 days at sea level
Time frame: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Respiratory Impedance (forced oscillation technique) after 4 days at sea level
Time frame: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Respiratory resistance (forced oscillation technique) after 4 days at sea level
Time frame: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
Respiratory reactance (forced oscillation technique) after 4 days at sea level
Time frame: From high altitude (Day 0, 2850m) to day 4 at sea level (approximately 5 days)
FEV1 pre-descent and after re-ascent (2850m)
Time frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Forced Vital Capacity FVC pre-descent and after re-ascent (2850m)
Time frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
FEV1/FVC pre-descent and after re-ascent (2850m)
Time frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory Impedance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Time frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory resistance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Time frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Respiratory reactance (forced oscillation technique) pre-descent and after re-ascent (2850m)
Time frame: Baseline at 2850m followed by a one-week stay at sea level to the day after re-ascent back to 2850m (time frame approximately 11 days)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Sep 2026.
- Individual participant dataSharing planned: Yes. Data will be provided upon request and based on a clear intention reviewed by an ethical review board.
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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.
Michael Furian, Prof. Dr. sc. ETH contact
Silvia Ulrich principal investigator
University Hospital Zurich, Departement of Pulmonology
Rodrigo Hoyos principal investigator
Hospital Carlos Andrade Marin of Quito, Ecuador
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Re-ascent from sea level to 2850m in people with Pulmonary Arterial Hypertension (PAH) and Pulmonary Vascular Disease, run by Silvia Ulrich Somaini 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 6 inclusion and 9 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: opening soon, as of the sponsor's last update on 4 Sep 2026. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Silvia Ulrich, Prof. Dr. med. (+41442552220, silvia.ulrich@usz.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
FEV1 after re-ascent to 2850m (time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 4 Sep 2026.