Effect of Long-term Oxygen Therapy on Exercise Capacity and Quality of Life in Patients With Pulmonary Arterial and Chronic Thromboembolic Pulmonary Hypertension

Study Overview
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Brief Summary
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In this randomized-controlled, cross-over trial the investigators test the effect of long-term oxygen therapy (> 16h/day) given for 5 weeks with a wash-out period between phases of 2 weeks on exercise performance and quality of life and many physiological parameters in patients with pulmonary arterial and chronic thromboembolic pulmonary hypertension.

Conditions
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Pulmonary Arterial and Chronic Thromboembolic Pulmonary Hypertension

Intervention / Treatment
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* Procedure: long term oxygen therapy


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: - Adult patients with established diagnosis of pulmonary arterial or chronic thromboembolic pulmonary hypertension (class I and IV according to the latest WHO classification scheme of Dana Point 2008) on optimized medical therapy and in stable condition for at least 4 weeks, who desaturate in the 6 minute walking test by =4% to values <92%. Exclusion criteria: Patients in unstable conditions requiring frequent therapeutic adaption pregnant women patients with pulmonary venous hypertension due to left heart diseases patients with relevant concomitant lung disease and severe daytime hypoxemia

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 85 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Supplemental oxygen<br>Supplemental oxygen 3 liters/minute given via a nasal cannula for 16 hours a day | Procedure: long term oxygen therapy<br> <br> |
| Sham Comparator: Sham room air<br>Room air given at a flow rate of 3 liters per minute for 16 hours a day | Procedure: long term oxygen therapy<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6 minute walk test | 6 minute walk distance according to american thoracic society (ATS) guidelines | 5 weeks | 
| Quality of life | QoL assessed by the short form of the medical outcome questionnaire (SF-36) physical functioning scale | 5 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Daily activity | measured by actigraphy | 5 week | 
| hemodynamics by echocardiography | Full echocardiographic assessment | 5 weeks | 
| quality of life | SF-36 | 5 weeks | 
| arterial blood gas | partial pressure of oxygen (PaO2) | 5 weeks | 
| operating hours of oxygen concentrator | efficacy of oxygen treatment | 5 weeks | 
| mean nocturnal oxygen saturation | Ambulatory Sleep Study | 5 weeks | 
| tests of cognitive performance | STROOP-Test | 5 weeks | 
| Quality of life | Minnesota living with heart failure questionnaire | 5 weeks | 
| Venous blood | N-terminal brain natriuretic peptide (NT-proBNP) | 5 weeks |