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Not yet recruitingNCT07797166Updated Sep 1, 2026

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

An interventional study of Re-Ascent sea level to 2850m in Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease and Six-minute Walk Test, 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 2026-09-01.

Sponsored by Silvia Ulrich Somaini · Not applicable, Interventional, and Supportive care

Phase
Not applicable
Study type
Interventional
Enrollment
20
Allocation
Not applicable
Ages
18 Years to 80 Years
Sex
All
01

Study 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 six-minute walking distance and other scores in patients with pulmonary arterial hypertension PAH, who live permanently >2600m.

Read the detailed description

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.

02

Conditions studied

  • Pulmonary Arterial Hypertension (PAH)
  • Pulmonary Vascular Disease
  • Six-minute Walk Test
  • NYHA
  • High Altitude Effects
  • High Altitude

Keywords

  • Hypoxia
  • High Altitude
  • six-minute walking distance
  • Pulmonary Arterial Hypertension
  • NYHA
  • Exercise testing
03

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

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

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)
04

Study design

Phase
Not applicable
Primary purpose
Supportive care
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
20 participants (estimated)

Study arms

  • Experimental
    Six-minute walking distance 6MWD at sea level and after re-ascent at 2850m

    Assessment of six-minute walking distance 6MWD and other scores after 7 days at sea level and after re-ascent from sea level back to 2850m by bus (in one day)

    Behavioral: Re-Ascent sea level to 2850m

Interventions

  • BehavioralRe-Ascent sea level to 2850m

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

05

What researchers measure

Primary outcomes

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

    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

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

Secondary outcomes

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

    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)

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

    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

    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)

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

    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

    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)

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

    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

    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)

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

    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

    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)

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

    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

    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)

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

    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

    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)

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

    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

    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)

06

Study locations

1 site
  • University Hospital of Zurich
    Zurich, 8091, Switzerland
07

References and documents

Individual participant data

Plan to share: Yes — Data will be provided upon request and based on a clear intention reviewed by an ethical review board.

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07797166
Lead sponsor
Silvia Ulrich Somaini
Responsible party
Silvia Ulrich Somaini (Prof. Dr. med., University of Zurich) — Sponsor-investigator
First posted
Sep 1, 2026
Start date
Sep 25, 2026 (estimated)
Primary completion
Oct 4, 2026 (estimated)
Completion
Dec 31, 2026 (estimated)
Last update
Sep 1, 2026

Study contacts

Silvia Ulrich, Prof. Dr. med.
Contact
silvia.ulrich@usz.ch
+41442552220
Michael Furian, Prof. Dr. sc. ETH
Contact
+41442552220
Silvia Ulrich
principal investigator · University Hospital Zurich, Departement of Pulmonology
Rodrigo Hoyos
principal investigator · Hospital Carlos Andrade Marin of Quito, Ecuador

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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