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NCT Number: NCT07797166

Assessment of Six-minute Walking Distance Between Sea Level LA vs. High Altitude HA After Re-ascent in Patients With Pulmonary Arterial Hypertension PAH

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 six-minute walking distance and other 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 High Altitude High Altitude Effects Hypertension, Pulmonary Hypoxia Lung Diseases NYHA 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

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 other scores 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.

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 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

Re-Ascent sea level to 2850m

Behavioral

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

Primary outcomes

  1. Six-minute walking distance after re-ascent to 2850m

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

    Difference/change in six-minute walking distance 6MWD between sea level (after one-week stay) and day after re-ascent at 2850m in patients with pulmonary arterial hypertension

Secondary outcomes

  1. SpO2 at rest and end-exercise after re-ascent to 2850m

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

    Difference/change in SpO2 (peripheral oxygen saturation) at rest and end-exercise between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  2. Heart rate at rest and end-exercise after re-ascent to 2850m

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

    Difference/change in heart rate at rest and end-exercise between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  3. Blood pressure at rest and end-exercise after re-ascent to 2850m

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

    Difference/change in blood pressure at rest and end-exercise between sea level (after one-week stay) and Day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  4. Dyspnea and leg discomfort sensation after re-ascent to 2850m

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

    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 sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  5. NYHA functional class after re-ascent to 2850m

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

    Difference/change in NYHA functional class (New York Heart Association Class I-IV, IV being the worst) at rest and end-exercise between sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  6. Quality of life after re-ascent to 2850m

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

    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 sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  7. General well-being after re-ascent to 2850m

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

    Difference/change in general well-being (Visual Analog Scale 10cm: the higher, the worse) between sea level (after one-week stay) and day after re-ascent to 2850m in patients with pulmonary arterial hypertension

  8. Six-minute walking distance pre-descent to after re-ascent

    Time frame: Baseline at 2850m followed by a one-week stay at sea level to day after re-ascent back to 2850m (time frame approximately 11 days)

    Difference/change in six-minute walking distance (6MWD) 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

  9. SpO2 at rest and end-exercise pre-descent to after re-ascent

    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)

    Difference/change in SpO2 (peripheral oxygen saturation) at rest and end-exercise 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

  10. Heart rate at rest and end-exercise pre-descent to after re-ascent

    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)

    Difference/change in heart rate at rest and end-exercise 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

  11. Blood pressure at rest and end-exercise pre-descent to after re-ascent

    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)

    Difference/change in blood pressure at rest and end-exercise 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

  12. Dyspnea and leg discomfort pre-descent to after re-ascent

    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)

    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 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

  13. NYHA functional class pre-descent to after re-ascent

    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)

    Difference/change in NYHA functional class (New York Heart Association Class I-IV, IV being the worst) 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

  14. Quality of life pre-descent to after re-ascent

    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)

    Difference/change in quality of life (EmPHasis-10: Score with 10 questions and 0-50 points, higher scores indicating poorer quality of life) 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

  15. General well-being pre-descent to after re-ascent

    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)

    Difference/change in general well-being (Visual Analog Scale 10cm: the higher, the worse) 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

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 1, 2026
Registry last updated
Sep 1, 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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