An interventional study of Re-ascent from sea level to 2850m in Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease and High Altitude Effects, sponsored by Silvia Ulrich Somaini. Not yet recruiting at 1 site in Switzerland. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-04.
Sponsored by Silvia Ulrich Somaini · Not applicable, Interventional, and Supportive care
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.
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.
699 studies on the registry are indexed under Pulmonary Arterial Hypertension; 140 are open to participants now.
This study's planned enrollment of 20 is below the median of 40 across 477 interventional studies indexed under Pulmonary Arterial Hypertension.
Browse Pulmonary Arterial Hypertension studies →Silvia Ulrich Somaini is the lead sponsor of 17 studies on the registry; 16 are open to participants now.
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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.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
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.
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
FEV1
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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)
Behavioral: Re-ascent from sea level to 2850m
Descent from 2850m to sea level with a stay for 7 days and re-ascent/return back to their usual living altitude at 2850m
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
Time frame: From Day 4 at sea level to the day after re-ascent (Day 9: approximately 6 days)
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
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
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
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
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
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
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
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
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
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
Difference/change in FEV1 between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
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
Difference/change in forced vital capacity FVC between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
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
Difference/change in FEV1/FVC between 2850m (prior to descent) and day 4 at sea level in patients with pulmonary arterial disease
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
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
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
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
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
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
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)
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
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)
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
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)
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
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)
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
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)
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
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)
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
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)
Plan to share: Yes — Data will be provided upon request and based on a clear intention reviewed by an ethical review board.
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Pulmonary Arterial Hypertension →
Silvia Ulrich Somaini