Clinical trial NCT03637153: Acute Exposure to High Altitude on Exercise Capacity
Official title: Acute Exposure to Hypoxia in Precapillary Pulmonary Hypertension: Physiological and Clinical Effects at Rest and During Exercise
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Pulmonary Hypertension
Keywords: exercise capacity
High Altitude
contant loaded exercise test
Lead sponsor: University of Zurich
Sponsor class: OTHER
First posted: 2018-08-17
Enrollment: 28
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Including a baseline assessment and assessments at Low altitude and High altitude
Primary purpose: PREVENTION

Brief summary: Randomized crossover Trial in patients with Pulmonary Hypertension (PAH, CTEPH) to assess the acute response to High Altitude (2500m above sea level) in constant loaded exercise capacity.

Detailed description: Low altitude baseline measurements will be performed in Zurich (460m asl) including Echocardiography, Right heart catheterization, 6MWT, pulmonary function test, clinical assessment and blood gas Analysis.

Randomly assigned to the order of testing, the participants will be tested in Low Altitude (Zurich, 470m) and at High Altitude (2500m).

Towards the end of the exposure after approximately 4 hours, the participants will perform a constant loaded exercise test on an Ergometer with a calculated resistance of their 60% max Workload.

The patients will be encouraged to perform these tests up to their physical exhaustion.

Eligibility criteria: Inclusion Criteria:

* Informed consent
* PH diagnosed according to internation Guidelines: mPAP ≥ 25 mmHg along with a PAWP ≤15 mmHg during right heart catheterization at the time of Initial diagnosis
* PH class 1 (PAH) or 4 (CTEPH)
* Stable condition, on the same medication for \> 4 weeks
* Patient live permanently at an altitude \< 1000m asl.

Exclusion Criteria:

* Resting PaO2 ≤7.3 kPA corresponding to the requirement of long-term oxygen therapy \> 16hour daily (nocturnal oxygen therapy alone is allowed)
* Severe daytime hypercapnia (pCO2 \> 6.5 kPa)
* Susceptibility to high altitude related diseases (AMS, HAPE, etc.) based on previous experienced discomfort at altitudes.
* Exposure to an altitude \>1500m for ≥3 nights during the last 4 weeks before the study participation
* Residence \> 1000m above sea level
* Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, neurological or orthopedic problems with Walking disability
* Women who are pregnant or breast feeding

Primary outcomes:
measure: endurance time at High Altitude
timeFrame: 1 day at altitude
Secondary outcomes:
Other outcomes:
Locations:
city: Zurich
country: Switzerland
facility: Respiratory Clinic, University Hospital of Zurich
Study officials:
affiliation: University of Zurich
name: Silvia Ulrich, Prof.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Schneider SR, Lichtblau M, Furian M, Mayer LC, Berlier C, Muller J, Saxer S, Schwarz EI, Bloch KE, Ulrich S. Cardiorespiratory Adaptation to Short-Term Exposure to Altitude vs. Normobaric Hypoxia in Patients with Pulmonary Hypertension. J Clin Med. 2022 May 14;11(10):2769. doi: 10.3390/jcm11102769.