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NCT Number: NCT07804524

Assessment of Total Pulmonary Resistance sPAP/CO Between High Altitude HA vs. Sea Level LA in Patients With Pulmonary Arterial Hypertension PAH

To study the effect of relocation from high altitude (Quito Ecuador: 2850m) to sea level on pulmonary resistance (sPAP/CO) and other hemodynamic outcomes in patients with pulmonary arterial hypertension PAH, who live permanently >2600m.

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Key information

Conditions

Pulmonary Arterial Hypertension (PAH) Altitude Sickness Cardiovascular Diseases Echocardiography Hemodynamic Changes High Altitude Hypertension Hypertension, Pulmonary Hypoxia Lung Diseases Pathological Conditions, Signs and Symptoms Pulmonary Arterial Hypertension Pulmonary Resistance Pulmonary Vascular Disease Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory Vascular Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University Hospital of Zurich

Zurich, 8091, Switzerland

About this study

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

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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)
  • Severely hypoxemic patients at 2850m 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)

Treatment and study plan

Descent from 2850m to sea level

Behavioral

Descent from 2850m to sea level with a stay for 7 days

Primary outcomes

  1. Pulmonary resistance (sPAP/CO) after 7 days at sea level

    Time frame: From high altitude (2850m) to day 5-7 at sea level

    Difference in sPAP/CO by echocardiography between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

Secondary outcomes

  1. Tricuspid regurgitation velocity TRV after 7 days at sea level

    Time frame: From high altitude (2850m) to day 5-7 at sea level

    Difference in tricuspid regurgitation velocity TRV between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

  2. Cardiac output CO after 7 days at sea level

    Time frame: From high altitude (2850) to day 5-7 at sea level

    Difference/change in cardiac output CO between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

  3. Tricuspid annular plan systolic excursion TAPSE after 7 days at sea level

    Time frame: From high altitude (2850m) to day 5-7 at sea level

    Difference/change in tricuspid annular plan systolic excursion TAPSE between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

  4. Right ventricular strain after 7 days at sea level

    Time frame: From high altitude (2850m) to Day 5-7 at sea level

    Difference/change in right ventricular strain between 2850m and day 5-7 at sea level in patients with pulmonary arterial hypertension

  5. Right atrial pressure RAP after 7 days at sea level

    Time frame: From high altitude (2850m) to Day 5-7 at sea level

    Difference/change in right atrial pressure RAP between 2850m and day 5-7 at sea level in patients with pulmonary arterial hypertension

  6. Fractional area change FAC after 7 days at sea level

    Time frame: From high altitude (2850m) to Day 5-7 at sea level

    Difference/change in fractional area change FAC between 2850m and day 5-7 at sea level in patients with pulmonary arterial hypertension

  7. PaO2 after 7 days at sea level

    Time frame: From high altitude (2850) to day 5-7 at sea level

    Difference/change in PaO2 (arterial blood gas analysis) between 2850m and sea level in patients with pulmonary arterial hypertension

  8. PaCO2 after 7 days at sea level

    Time frame: From high altitude (2850) to day 5-7 at sea level

    Difference/change in PaCO2 (arterial blood gas analysis) between 2850m and sea level in patients with pulmonary arterial hypertension

  9. Hemoglobin after 7 days at sea level

    Time frame: From high altitude (2850) to day 5-7 at sea level

    Difference/change in hemoglobin (arterial blood gas analysis) between 2850m and sea level in patients with pulmonary arterial hypertension

  10. pH after 7 days at sea level

    Time frame: From high altitude (2850) to day 5-7 at sea level

    Difference/change in pH(arterial blood gas analysis) between 2850m and sea level in patients with pulmonary arterial hypertension

  11. Acclimatization-Effect of pulmonary resistance (sPAP/CO) at sea level

    Time frame: From Day 2 to Day 5-7 at sea level

    Difference/change in pulmonary resistance (sPAP/CO) within a stay at sea level of 7 days (after relocation from high altitude)

  12. Acclimatization-Effect of tricuspid regurgitation velocity TRV at sea level

    Time frame: From Day 2 to Day 5-7 at sea level

    Difference/change in tricuspid regurgitation velocity TRV within a stay at sea level of 7 days (after relocation from high altitude)

  13. Acclimatization-Effect of cardiac output CO at sea level

    Time frame: From Day 2 to Day 5-7 at sea level

    Difference/change in cardiac output CO within a stay at sea level of 7 days (after relocation from high altitude)

  14. Acclimatization-Effect of tricuspid annular plan systolic excursion TAPSE at sea level

    Time frame: From Day 2 to day 5-7 at sea level

    Difference/change in tricuspid annular plan systolic excursion TAPSE within a stay at sea level for 7 days (after relocation from high altitude)

  15. Acclimatization-Effect of right ventricular strain at sea level

    Time frame: From Day 2 to Day 5-7 at sea level

    Difference/change in right ventricular strain within a stay at sea level for 7 days (after relocation from high altitude)

  16. Acclimatization-Effect of right atrial pressure RAP at sea level

    Time frame: From Day 2 to Day 5-7 at sea level

    Difference/change in right atrial pressure RAP within a stay at sea level for 7 days (after relocation from high altitude)

  17. Acclimatization-Effect of fractional area change FAC at sea level

    Time frame: From Day 2 to Day 5-7 at sea level

    Difference/change in fractional area change FAC within a stay at sea level for 7 days (after relocation from high altitude)

  18. Acclimatization-Effect of PaO2 at sea level

    Time frame: From Day 2 to Day 7 at sea level

    Difference/change in PaO2 (arterial blood gas analysis) within a stay at sea level for 7 days (after relocation from high altitude)

  19. Acclimatization-Effect of PaCO2 at sea level

    Time frame: From Day 2 to Day 7 at sea level

    Difference/change in PaCO2 (arterial blood gas analysis) within a stay at sea level for 7 days (after relocation from high altitude)

  20. Acclimatization-Effect of hemoglobin at sea level

    Time frame: From Day 2 to Day 7 at sea level

    Difference/change in hemoglobin (arterial blood gas analysis) within a stay at sea level for 7 days (after relocation from high altitude)

  21. Acclimatization-Effect of pH at sea level

    Time frame: From Day 2 to Day 7 at sea level

    Difference/change in pH (arterial blood gas analysis) within a stay at sea level for 7 days (after relocation from high altitude)

Study contacts

Contact information is provided by the study sponsor or research team.

Michael Furian, Prof. Dr. sc. ETH

CONTACT

+41442552220

Silvia Ulrich, Prof. Dr. med.

CONTACT

[email protected]

+41442552220

Sponsors and collaborators

Lead sponsor

Silvia Ulrich Somaini

Other

Registry information

Official study 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

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Sep 4, 2026
Registry last updated
Sep 4, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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