Assessment of Six-minute Walking Distance 6MWD Between High Altitude HA vs. Sea Level LA in Patients With Pulmonary Arterial Hypertension PAH

Effect of a One-week Descent From 2850m to Sea Level and Re-ascent in Patients With Pulmonary Arterial Hypertension and Healthy Controls Permanently Living > 2600m on Pulmonary Hemodynamics, Exercise Capacity, Blood Oxygenation, Sleep Disordered Breathing and Further Outcomes

To study the effect of relocation from high altitude (Quito: 2850m) to sea level on six-minute walking distance and scores in patients with pulmonary arterial hypertension PAH, who live permanently >2600m.

The aim of this research is to investigate the six-minute walking distance and scores before and after descent (high altitude near their living altitude vs. sea level) in patients with diagnosed pulmonary arterial hypertension according to guidelines, who permanently live at high altitude over 2600m.

Inclusion Criteria:

• Adult patients aged 18-80 years and of all genders
• Permanent residence > 2600 m
• Diagnosis of pulmonary arterial hypertension PAH (PAHHA-Group) according to guidelines
• Patients are stable on therapy
• NYHA (new york heart association) functional class I-III
• 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 < 2600m
• Patients who traveled and stayed overnight at altitudes <2000 m in the past 4 weeks
• 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 having persistent SpO2 (oxygen saturation by pulse-oximetry) <80% on ambient air.
• Patient with a non-corrected ventricular septum defect
• Relevant concomitant other disease of the heart, kidney, liver, blood (anemia hemoglobin<11 g/dl)