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

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: Pulmonary Arterial Hypertension; Chronic Thromboembolic Pulmonary Hypertension; Pulmonary Vascular Disorder
• Intervention / Treatment: Other: 6-minute walk distance (6MWD) test on ambient air; Other: 6-minute walk distance test with supplemental oxygen

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

Study Locations

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

Participation Criteria

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

How is the study designed?

Design Details

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

Number of Arms

2

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	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	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	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	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	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	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

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

Study record dates

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: Pulmonary Hypertension; Pulmonary Arterial Hypertension; Chronic Thromboembolic Pulmonary Hypertension; Pulmonary Vascular Disease; Supplemental Oxygen Therapy; 6 Minute Walking Distance
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Hypertension; Pulmonary Arterial Hypertension; Hypertension, Pulmonary
• 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