Exercise Performance on Ambient Air vs. Low-Flow Oxygen Therapy in Pulmonary Vascular Disease (PVD)

December 2, 2025 updated by: University of Zurich

Exercise Performance on Ambient Air vs. Commonly Prescribed Nasal Low Oxygen Therapy - a Non-inferiority Trial in Patients With Exercise Induced Desaturation Due to Pulmonary Vascular Disease (PVD)

The investigators aim to study the effect of SOT in Swiss residents with pulmonary vascular diseases (PVD) defined as pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Participants with PVD diagnosed with precapillary PH with right heart catheterization and classified to groups 1 and 4 (PAH or CTEPH) who live in Switzerland will have 6-minute walk distance (6MWD) test with and without SOT approximately 3l/min via nasal cannula according to a randomized cross-over design.

The trial aims to test that the 6MWD with SOT is non-inferior to a 6MWD in the same participant under ambient air.

The effect size was estimated with a difference of less or equal to 35m compared under SOT compared to ambient air.

Study Type

Interventional

Enrollment (Actual)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Switzerland
    • Canton of Zurich
      • Zurich, Canton of Zurich, Switzerland, 8091
        • University Hospital Zurich

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Minimum 18 years of age
  • Written informed consent
  • Patients with diagnosed pulmonary arterial hypertension (PAH), distal chronic thromboembolic pulmonary hypertension (CTEPH)
  • Former desaturation under exercise defined as Spo2-decrease >3%
  • Treated with a stable drug therapy (with no changes for at least 14 days prior to screening)

Exclusion Criteria:

  • Severe hypoxemia needing supplemental oxygen therapy defined as partial pressure of O2 (PaO2) < 6.9 Kilopascal (kPa)
  • Pregnancy
  • Unability or contraindications to undergo the investigated intervention
  • Unability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Ambient air
Patient will perform tests at University Hospital Zurich
Other: 6-minute walk distance (6MWD) test on ambient air
6-minute walk distance (6MWD) test will be performed on ambient air according to clinical standards
Active Comparator: SOT via basal canula
Supplemental Oxygen Therapy (SOT) at approximately 3l/min will be provided via nasal canula from a small oxygen concentrator while the patient performs tests at University Hospital Zurich.
Other: 6-minute walk distance test with supplemental oxygen
6-minute walk distance (6MWD) test will be performed according to clinical standards additionally with supplemental oxygen therapy (approximately 3l/min, nasal)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
6-minute walk distance (6MWD) with supplemental oxygen therapy (SOT) vs. ambient air
Time Frame: after 6 minutes
Change in 6MWD in meter between SOT via nasal cannula vs. ambient air
after 6 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
SpO2 at rest and peak 6MWD with SOT vs. ambient air
Time Frame: after 6 minutes
Change of the arterial oxygen saturation by pulse oximeter (SpO2) at rest and at peak 6MWD with SOT approximately 3l /min vs. ambient air
after 6 minutes
Heart rate at rest and peak 6MWD with SOT vs. ambient air
Time Frame: after 6 minutes
Change of heart rate (bpm) at rest and at peak 6MWD with SOT vs. ambient air
after 6 minutes
Blood pressure at rest and peak 6MWD with SOT vs. ambient air
Time Frame: after 6 minutes
Change of Blood pressure (mmHg) at rest and at peak 6MWD with SOT vs. ambient air
after 6 minutes
Borg dyspnea atrest and peak 6MWD with SOT vs. ambient air
Time Frame: 6 minutes
Change of Borg dyspnea scale (CR10, 0-10 where 10 is the worst dyspnea) at rest and at peak 6MWD with SOT vs. ambient air
6 minutes
Borg leg fatigue scale at rest and peak 6MWD with SOT vs. ambient air
Time Frame: 6 minutes
Change of Borg leg fatigue scale (CR10, 0-10 where 10 is the strongest led fatugue) at rest and at peak 6MWD with SOT vs. ambient air
6 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Zurich

Investigators

  • Principal Investigator: Silvia Ulrich, Prof. Dr., University Hospital Zurich, Department of Pulmonology

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2024

Primary Completion (Actual)

July 1, 2025

Study Completion (Actual)

July 1, 2025

Study Registration Dates

First Submitted

April 17, 2024

First Submitted That Met QC Criteria

April 22, 2024

First Posted (Actual)

April 25, 2024

Study Record Updates

Last Update Posted (Actual)

December 10, 2025

Last Update Submitted That Met QC Criteria

December 2, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • PVD_6MWD_SOT

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will be provided upon request and based on a clear intention reviewed by an ethical review board

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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