High Altitude (HA) Residents With Pulmonary Vascular Diseases (PVD), 6 Minute Walk Distance (6MWD) Assessed at 2840m (HA) With and Without Supplemental Oxygen Therapy (SOT)

Study Overview
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Brief Summary
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The investigators aim to study the effect of SOT in participants with pulmonary vascular diseases (PVD) defined as pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension (PH) who permanently live >2500m on 6-minute walk distance (6MWD) assessed at 2840m.

Detailed Description
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Participants with PVD diagnosed with precapillary PH with right heart catheterization and classified to groups 1 and 4 (PAH or CTEPH) who permanently live at HA >2500 (PVDHA) will have 6-minute walk distance near their living altitude in Quito at 2840m with and without SOT at 3l/min via nasal cannula according to a randomized cross-over design.

Official Title
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Effect of Supplemental Oxygen Therapy (SOT) in Patients With Pulmonary Vascular Diseases (PVD) Defined as Pulmonary Arterial Hypertension or Chronic Thromboembolic Pulmonary Hypertension (PH) Who Permanently Live >2500m on 6-minute Walk Distance (6MWD)

Conditions
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Pulmonary Vascular Disease, Pulmonary Artery Hypertension, Chronic Thromboembolic Pulmonary Hypertension

Intervention / Treatment
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* Other: 6-minute walk distance (6MWD) test
* Other: 6-minute walk distance (6MWD) test with supplemental oxygen (3 l/min, nasal)


Participation Criteria
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Eligibility Criteria
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IInclusion Criteria: Adult patients 18-80 years old of both genders, Residence > 2500m of altitude diagnosed with precapillary PH (mean pulmonary artery pressure (mPAP) >20 mmHg, pulmonary artery wedge pressure (PAWP) ≤15 mmHg and pulmonary vascular resistance (PVR) ≥2 wood units (WU) by right heart catheterization) with PH being classified as PAH or CTEPH according to guidelines Patients stable on therapy New York Heart Association (NYHA) functional class I-III Provided 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 < 2500m. 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 have persistent oxygen saturation by pulseoximetry (SpO2) <80% on ambient air. Patients with chronic mountain sickness (Hemoglobin > 19 g/dl in women, >21 g/dl in men) Patient with a non-corrected ventricular septum defect Relevant concomitant other disease of the heart, kidney, liver, blood (anemia hemoglobin<11 g/dl)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Each participant works as its own perfect control
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Ambient air<br>Patient will perform tests on ambient air at 2840 m | Other: 6-minute walk distance (6MWD) test<br>* 6-minute walk distance (6MWD) test will be performed according to clinical standards<br>|
| Experimental: SOT via nasal canula<br>Supplemental oxygen therapy (SOT) at 3l/min will be provided via a nasal cannula from a small oxygen bottle carried on the back according to standard care | Other: 6-minute walk distance (6MWD) test with supplemental oxygen (3 l/min, nasal)<br>* 6-minute walk distance (6MWD) test will be performed according to clinical standards additionally with supplemental oxygen therapy (3l/min, nasal)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6-minute walk distance (6MWD) with supplemental oxygen therapy (SOT) vs. ambient air at 2840m | Change in 6MWD in meter between SOT 3l/min via nasal cannula vs. ambient air at 2840m | after 6 minute | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SpO2 at rest and peak 6MWD with SOT vs. ambient air at 2840m | Change of the arterial oxygen saturation by pulseoximetry (SpO2) at rest and at peak 6MWD with SOT 3l /min vs. ambient air at 2840 m | 6 minutes | 
| Heart rate at rest and peak 6MWD with SOT vs. ambient air at 2840m | Change of heart rate (bpm) at rest and at peak 6MWD with SOT 3l /min vs. ambient air at 2840 m | 6 minutes | 
| Blood pressure at rest and peak 6MWD with SOT vs. ambient air at 2840m | Change of Blood pressure (mmHg) at rest and at peak 6MWD with SOT 3l /min vs. ambient air at 2840 m | 6 minutes | 
| Borg dyspnea scale at rest and peak 6MWD with SOT vs. ambient air at 2840m | Change of Borg dyspnea scale at rest and at peak 6MWD with SOT 3l /min vs. ambient air at 2840 m | 6 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pulmonary Hypertension, Hypoxia, Supplemental Oxygen Therapy, Pulmonary arterial hypertension, Chronic Thromboembolic Pulmonary Hypertension, High altitude, Pulmonary vascular disease