Exercise Endurance Time on the 2nd Day at 2500 m High Altitude

Study Overview
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Brief Summary
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The impact of a sojourn at 2500 m of high altitude for 26-30 h on constant work-rate exercise test time in patients with precapillary pulmonary hypertension

Detailed Description
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Patients with pulmonary hypertension will perform a constant work-rate exercise test at low altitude (450m) and at high altitude 2500m in a randomized-cross-over sequence protocol. The constant work-rate exercise test time and other measures will be assessed

Official Title
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The Impact of Hypoxia on Patients With Precapillary Pulmonary Hypertension and Treatment of Adverse Effects

Conditions
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High Altitude Pulmonary Hypertension

Intervention / Treatment
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* Procedure: High altitude exposure
* Procedure: Low altitude exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent as documented by signature PH class I (PAH) or IV (CTEPH) diagnosed according to guidelines: mean pulmonary artery pressure >20 mmHg, pulmonary vascular resistance ≥3 wood units, pulmonary arterial wedge pressure ≤15 mmHg during baseline measures at the diagnostic right-heart catheterization Exclusion Criteria: resting partial pressure of oxygen <8 kilopascal at Zurich at 490 m low altitude exposure to an altitude >1000 m for ≥3 nights during the last 2 weeks before the study inability to follow the procedures of the study other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)

Ages Eligible for Study
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Minimum Age: 18 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: Screening
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Constant work-rate at altitude 2500 m above sea level (high altitude)<br>Cycling at high altitude | Procedure: High altitude exposure<br>* Exposure to 2500m of altitude<br>Procedure: Low altitude exposure<br>* Exposure to 490 m<br>|
| Active Comparator: Constant work-rate at altitude 470 m above sea level (low altitude)<br>Cycling at low altitude | Procedure: High altitude exposure<br>* Exposure to 2500m of altitude<br>Procedure: Low altitude exposure<br>* Exposure to 490 m<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cycle constant work-rate exercise test | Difference in cycle constant work-rate exercise test (CWRET) time at 2500 vs. 490 m (Time Frame 24 to 30 hours) | 30 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | Difference in cardiorespiratory measurements: Heart rate, during a cycle constant work-rate exercise test (CWRET) time at high altitude vs. low altitude | 30 hours | 
| Ventilation in liters per minute | Difference in cardiorespiratory measurements: Ventilation assessed in liters per minute, during a cycle constant work-rate exercise test (CWRET) time at high altitude vs. low altitude | 30 hours | 
| Oxygen uptake | Difference in cardiorespiratory measurements: oxygen uptake, during a cycle constant work-rate exercise test (CWRET) time at high altitude vs. low altitude | 30 hours | 
| Oxygen saturation | Difference in cardiorespiratory measurements: Oxygen saturation, during a cycle constant work-rate exercise test (CWRET) time at high altitude vs. low altitude | 30 hours | 
| Partial pressure or oxygen | Difference in partial pressure of oxygen at the beginning and end of a cycle constant work-rate exercise test (CWRET) time at high altitude vs. low altitude | 30 hours | 
| Tricuspid pressure gradient | Trans-tricuspid pressure gradient by echocardiography | 30 hours | 
| Borg dyspnoea scale | Difference in post-exercise Borg dyspnoea and leg fatigue scale during a cycle constant work-rate exercise test (CWRET) time at high altitude vs. low altitude | 30 hours | 
| Visual analogue scale | Difference in baseline in symptoms assessed by the Visual Analogue Scale at high altitude vs. low altitude | 30 hours | 
| sit-to-stand test frequency | Difference in baseline in sit-to-stand test frequency of standing up from a chair in a minute at high altitude vs. low altitude | 30 hours | 
| 6 minute walk test | Difference in baseline in 6 minute walk test distance at high altitude vs. low altitude | 30 hours |