Blood Markers Predict Effect of Normobaric Hypoxia at Rest and During Exercise in Patients With Pulmonary Hypertension

Hemodynamic Effects of Acute Normobaric Hypoxia During Exercise in Patients With Pulmonary Hypertension: Single-center Randomized Controlled Trial

To study the effect of acute normobaric hypoxia during exercise in patients with pulmonary hypertension on blood markers (serum markers of iron and red blood cell homeostasis and micro-RNAs known to be associated with PH).

Inclusion Criteria:

• Informed consent as documented by signature (Appendix Informed Consent Form)
• 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 Zürich altitude on ambient air
• 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
• patients who take nitrates
• other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)