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Not yet recruitingNCT07804693Updated Sep 4, 2026

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

An interventional study of Re-Ascent from sea level to 2850m in Pulmonary Arterial Hypertension (PAH), Pulmonary Vascular Disease and High Altitude, 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 2026-09-04.

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 pulmonary resistance (sPAP/CO) and other hemodynamic outcomes in patients with pulmonary arterial hypertension PAH, who live permanently >2600m.

Read the detailed description

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

02

Conditions studied

  • Pulmonary Arterial Hypertension (PAH)
  • Pulmonary Vascular Disease
  • High Altitude
  • Echocardiography
  • Pulmonary Resistance

Keywords

  • Pulmonary Arterial Hypertension (PAH)
  • Hypoxia
  • High Altitude
  • Pulmonary Hypertension
  • Pulmonary Resistance
  • Echocardiography
  • hemodynamics
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
    Pulmonary resistance (sPAP/CO) at sea level and after re-ascent at 2850m

    Assessment of pulmonary resistance (sPAP/CO) and other hemodynamic parameters after 7 days at sea level with re-ascent from sea level back to 2850m by bus (in one day) and assessment of the same outcomes

    Behavioral: Re-Ascent from sea level to 2850m

Interventions

  • BehavioralRe-Ascent from 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. Pulmonary resistance (sPAP/CO) after re-ascent to 2850m

    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

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

Secondary outcomes

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

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

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

    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

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

  7. PaO2 after re-ascent to 2850m

    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

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

  8. PaCO2 after re-ascent to 2850m

    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

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

  9. Hemoglobin after re-ascent to 2850m

    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

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

  10. pH after re-ascent to 2850m

    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

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

  11. Pulmonary resistance (sPAP/CO) pre-descent to after re-ascent

    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

    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. Tricuspid regurgitation velocity TRV pre-descent to after re-ascent

    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

    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. Cardiac output CO pre-descent to after re-ascent

    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

    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. Tricuspid annular plan systolic excursion TAPSE pre-descent to after re-ascent

    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

    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. Right ventricular strain pre-descent to after re-ascent

    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

    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)

  16. Right atrial pressure RAP pre-descent to after re-ascent

    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

    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)

  17. Fractional area change FAC pre-descent to after re-ascent

    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

    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)

  18. PaO2 pre-descent to after re-ascent

    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

    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)

  19. PaCO2 pre-descent to after re-ascent

    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

    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)

  20. Hemoglobin pre-descent to after re-ascent

    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

    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)

  21. pH pre-descent to after re-ascent

    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

    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
NCT07804693
Lead sponsor
Silvia Ulrich Somaini
Responsible party
Silvia Ulrich Somaini (Prof. Dr. med., University of Zurich) — Sponsor-investigator
First posted
Sep 4, 2026
Start date
Sep 25, 2026 (estimated)
Primary completion
Oct 4, 2026 (estimated)
Completion
Dec 31, 2026 (estimated)
Last update
Sep 4, 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
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