AzTrials
AzTrials

Pulmonary Arterial Hypertension (PAH)NCT07804693

Assessment of Total Pulmonary Resistance sPAP/CO Between Sea Level LA vs. High Altitude HA After Re-ascent 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.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
Search all trials

Trial summary

To study the effect of a re-ascent after a one-week stay at sea level (after prior descent from 2850m) to high altitude (Quito Ecuador: 2850m) on pulmonary resistance (sPAP/CO) and other hemodynamic outcomes in patients with pulmonary arterial hypertension PAH, who live permanently >2600m. Read more about this study

Who is it for?
Ages 18 to 80 years
What is being tested?
Re-Ascent from sea level to 2850m
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.

Silvia Ulrich, Prof. Dr. med. contact

+41442552220

silvia.ulrich@usz.ch

Michael Furian, Prof. Dr. sc. ETH contact

+41442552220

Switzerland1 site
  • University Hospital of Zurich

    Zurich, 8091

Other trials in Switzerland

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 after a one-week stay at sea level (after prior descent from 2850m) to high altitude (Quito Ecuador: 2850m) on pulmonary resistance (sPAP/CO) and other hemodynamic outcomes in patients with pulmonary arterial hypertension PAH, who live permanently >2600m.

Read the detailed description

The aim of this research is to investigate the pulmonary resistance (sPAP/CO) by echocardiography and other hemodynamic outcomes before and after re-ascent (sea level for 7 days vs. re-ascent to 2850m) in patients with diagnosed pulmonary arterial hypertension according to guidelines, who permanently live at high altitude over 2600m

Being tested
Re-Ascent from sea level to 2850m
Keywords
Pulmonary Arterial Hypertension (PAH), Hypoxia, High Altitude, Pulmonary Hypertension, Pulmonary Resistance, Echocardiography, hemodynamics
Medical subject headings
Pulmonary Arterial Hypertension, Altitude Sickness, Hypoxia, Hypertension, Pulmonary

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

    After 7 days at sea level return/re-ascent to their usual living altitude at 2850m

Study groups in NCT07804693
Study groupRoleWhat they receive
Pulmonary resistance (sPAP/CO) at sea level and after re-ascent at 2850mExperimentalAssessment of pulmonary resistance (sPAP/CO) and other hemodynamic parameters after 7 days at sea level with re-ascent from sea level back to 2850m by bus (in one day) and assessment of the same outcomes
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.

  1. Pulmonary resistance (sPAP/CO) after re-ascent to 2850m

    Difference in sPAP/CO by echocardiography between sea level (after one-week stay) and day after re-ascent at 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to day after re-ascent

Secondary outcomes (21)
  1. Tricuspid regurgitation velocity TRV after re-ascent to 2850m

    Difference/change in tricuspid regurgitation velocity TRV between sea level (after one-week stay) and day after re-ascent at 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to day after re-ascent

  2. Cardiac output CO after re-ascent to 2850m

    Difference/change in cardiac output CO between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to the day after re-ascent

  3. Tricuspid annular plan systolic excursion TAPSE after re-ascent to 2850m

    Difference/change in tricuspid annular plan systolic excursion TAPSE between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to day after re-ascent

  4. Right ventricular strain after re-ascent to 2850m

    Difference/change in right ventricular strain between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to day after re-ascent

  5. Right atrial pressure RAP after re-ascent to 2850m

    Difference/change in right atrial pressure RAP between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to day after re-ascent

  6. Fractional area change FAC after re-ascent to 2850m

    Difference/change in fractional area change FAC between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 5-7 at sea level to day after re-ascent

  7. PaO2 after re-ascent to 2850m

    Difference/change in PaO2 (arterial blood gas analysis) between sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 7 at sea level to day after re-ascent (time frame of 3 days)

  8. PaCO2 after re-ascent to 2850m

    Difference/change in PaCO2 (arterial blood gas analysis) between sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 7 at sea level to day after re-ascent (time frame of 3 days)

  9. Hemoglobin after re-ascent to 2850m

    Difference/change in hemoglobin (arterial blood gas analysis) between sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 7 at sea level to day after re-ascent (time frame of 3 days)

  10. pH after re-ascent to 2850m

    Difference/change in pH (arterial blood gas analysis) between sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

    Measured: From Day 7 at sea level to day after re-ascent (time frame of 3 days)

  11. Pulmonary resistance (sPAP/CO) pre-descent to after re-ascent

    Difference/change in pulmonary resistance (sPAP/CO) 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)

  12. Tricuspid regurgitation velocity TRV pre-descent to after re-ascent

    Difference/change in tricuspid regurgitation velocity TRV 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)

  13. Cardiac output CO pre-descent to after re-ascent

    Difference/change in cardiac output CO 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)

  14. Tricuspid annular plan systolic excursion TAPSE pre-descent to after re-ascent

    Difference/change in tricuspid annular plan systolic excursion TAPSE 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)

  15. Right ventricular strain pre-descent to after re-ascent

    Difference/change in right ventricular strain 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)

  16. Right atrial pressure RAP pre-descent to after re-ascent

    Difference/change in right atrial pressure RAP 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)

  17. Fractional area change FAC pre-descent to after re-ascent

    Difference/change in fractional area change FAC 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)

  18. PaO2 pre-descent to after re-ascent

    Difference/change in PaO2 (arterial blood gas analysis) 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)

  19. PaCO2 pre-descent to after re-ascent

    Difference/change in PaCO2 (arterial blood gas analysis) 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)

  20. Hemoglobin pre-descent to after re-ascent

    Difference/change in hemoglobin (arterial blood gas analysis) 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)

  21. pH pre-descent to after re-ascent

    Difference/change in pH (arterial blood gas analysis) 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.

  1. First posted4 Sep 2026
  2. Study start25 Sep 2026 (estimated)
  3. Primary completion4 Oct 2026 (estimated)
  4. Study completion31 Dec 2026 (estimated)

Resources

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 diagnosed with pulmonary arterial hypertension living permanently \> 2600m around Quito (Ecuador) will be assessed after 7 days at sea level and after re-ascent to 2850m
Masking
None (open label)
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07804693
Sponsor's protocol ID
Ec_LAvsHA_sPAP/CO_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

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?

Pulmonary resistance (sPAP/CO) after re-ascent to 2850m (time frame: From Day 5-7 at sea level to day after re-ascent). 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.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in