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NCT Number: 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

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.

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Key information

Conditions

Pulmonary Arterial Hypertension (PAH) Altitude Sickness Cardiovascular Diseases Echocardiography 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 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 from sea level to 2850m

Behavioral

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

Primary outcomes

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

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

    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

Secondary outcomes

  1. Tricuspid regurgitation velocity TRV after re-ascent to 2850m

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

  7. PaO2 after re-ascent to 2850m

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

    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

  8. PaCO2 after re-ascent to 2850m

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

    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

  9. Hemoglobin after re-ascent to 2850m

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

    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

  10. pH after re-ascent to 2850m

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

    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

  11. Pulmonary resistance (sPAP/CO) 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 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

  12. Tricuspid regurgitation velocity TRV 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 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

  13. Cardiac output CO 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 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

  14. Tricuspid annular plan systolic excursion TAPSE 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 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

  15. Right ventricular strain 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 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

  16. Right atrial pressure RAP 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 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

  17. Fractional area change FAC 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 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

  18. PaO2 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 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

  19. PaCO2 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 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

  20. Hemoglobin 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 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

  21. pH 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 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

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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