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NCT Number: NCT07804472

Assessment of Six-minute Walking Distance 6MWD 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: 2850m) to sea level on six-minute walking distance and scores 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 High Altitude High Altitude Effects Hypertension Hypertension, Pulmonary Hypoxia Lung Diseases Pathological Conditions, Signs and Symptoms Pulmonary Arterial Hypertension Pulmonary Vascular Disease Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory Six-minute Walk Test 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 six-minute walking distance and scores before and after descent (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 Quito: permanently having persistent SpO2 (oxygen saturation by pulse-oximetry) <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 stay for 7 days

Primary outcomes

  1. Six-minute walking distance (m) after 7 days at sea level

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

    Difference/change in six-minute walking distance 6MWD between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

Secondary outcomes

  1. SpO2 (peripheral oxygen saturation, %) at rest and end-exercise after 7 days at sea level

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

    Difference/change in SpO2 (peripheral oxygen saturation) at rest and end-exercise between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

  2. Heart rate (beats per minute) at rest and end-exercise after 7 days at sea level

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

    Difference/change in heart rate at rest and end-exercise between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

  3. Blood pressure (mmHg) at rest and end-exercise after 7 days at sea level

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

    Difference/change in blood pressure at rest and end-exercise between 2850m and Day 5-7 at sea level in patients with pulmonary arterial hypertension

  4. Dyspnea and leg discomfort sensation after 7 days at sea level

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

    Difference/change in dyspnea and leg discomfort sensation (assessed with BORG-CR10-Scale, Category Rating 0-10 with 10 being the most dyspnea/leg discomfort) at rest and end-exercise between 2850m and 5-7 days at sea level in patients with pulmonary arterial hypertension

  5. NYHA functional class (1-4) after 7 days at sea level

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

    Difference/change in NYHA functional class (New York Heart Association Class I-IV, IV being the worst) at rest and end-exercise between 2850m and 5-7 days at sea level in patients with pulmonary arterial hypertension

  6. Quality of life after 7 days at sea level

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

    Difference/change in quality of life score (EmPHasis-10: Score with 10 questions and 0-50 points, higher scores indicating poorer quality of life) between 2850m and 5-7 days at sea level in patients with pulmonary arterial hypertension

  7. General well-being after 7 days at sea level

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

    Difference/change in general well-being (Visual Analog Scale 10cm: the higher, the worse) between 2850m and day 5-7 at sea level in patients with pulmonary arterial hypertension

  8. Acclimatization-effect of six-minute walking distance (m) at sea level

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

    Difference/change in six-minute walking distance (6MWD) within a stay at sea level of 7 days (after descent from 2850m) in patients with pulmonary arterial hypertension

  9. Acclimatization-Effect of SpO2 (%) at rest and end-exercise at sea level

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

    Difference/change in SpO2 (peripheral oxygen saturation) at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in patients with pulmonary arterial hypertension

  10. Acclimatization-Effect of heart rate (beats per minute) at rest and end-exercise at sea level

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

    Difference/change in heart rate at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in patients with pulmonary arterial hypertension

  11. Acclimatization-Effect of blood pressure (mmHg) at rest and end-exercise at sea level

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

    Difference/change in blood pressure at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in patients with pulmonary arterial hypertension

  12. Acclimatization-Effect of dyspnea and leg discomfort at sea level

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

    Difference/change in dyspnea and leg discomfort (assessed with BORG-CR10-Scale, Category Rating 0-10 with 10 being the most dyspnea/leg discomfort) at rest and end-exercise within a stay at sea level of 7 days (after descent from 2850m) in patients with pulmonary arterial hypertension

  13. Acclimatization-Effect of NYHA functional class (1-4) at sea level

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

    Difference/change in NYHA functional class (New York Heart Association Class I-IV, IV being the worst) at rest and end-exercise within a stay of 7 days at sea level (after descent from 2850m) in patients with pulmonary arterial hypertension

  14. Acclimatization-Effect of Quality of Life at sea level

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

    Difference/change in quality of life (EmPHasis-10: Score with 10 questions and 0-50 points, higher scores indicating poorer quality of life) within a stay of 7 days at sea level (after descent from 2850m) in patients with pulmonary arterial hypertension

  15. Acclimatization-Effect of general well-being at sea level

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

    Difference/change in general well-being (Visual Analog Scale 10cm: the higher, the worse) within a stay of 7 days at sea level (after descent from 2850m) in patients with pulmonary arterial hypertension

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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