Effect of Oxygen Therapy for Patients With Precapillary Pulmonary Hypertension Who Experience an Altitude Related Adverse Health Effect (ARAHE) During 30h Exposure to 2500m

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

To study whether oxygen therapy titrated to maintain oxygenation (SpO2) > 90% at 2500m would resolve altitude-related adverse health effects, symptoms and impaired exercise during 30h exposure to high altitude.

Patients with pulmonary hypertension who reveal an altitude-related adverse health effects at 2500m will be given oxygen therapy by nasal cannula titrated to maintain the oxygen saturation above 90%. The study will investigate, whether this measure will restore altitude-induced impairment to baseline levels at low altitude.

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)