Assessment of Six-minute Walking Distance Between Sea Level LA vs. High Altitude HA After Re-ascent 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 a re-ascent after a one-week stay at sea level (after prior descent from 2850m) to high altitude (Quito Ecuador: 2850m) on six-minute walking distance and other 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 other scores before and after re-ascent (sea level for 7 days vs. re-ascent to 2850m) 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 pulseoximetry) <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)