Acute Exposure to High Altitude on Exercise Capacity

Acute Exposure to Hypoxia in Precapillary Pulmonary Hypertension: Physiological and Clinical Effects at Rest and During Exercise

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.

Study Overview

• Status: Completed
• Conditions: Pulmonary Hypertension
• Intervention / Treatment: Other: Assessment at Low Altitude (470m above sea level); Other: Exposure to High Altitude (2500m above sea level)

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.

• Study Type: Interventional
• Enrollment (Actual): 28
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Zurich, Switzerland, 8091
    • Respiratory Clinic, University Hospital of Zurich

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Order A; Firstly, the participants will have their assessments at low altitude (Low altitude: 470m above sea level) in Zurich and consecutively the exposure to High Altitude (Säntis; 2500m above sea Level).	Other: Assessment at Low Altitude (470m above sea level); Assessment at Low Altitude (in Zurich; 470m above sea level) in order to compare this data with High altitude exposure; Other: Exposure to High Altitude (2500m above sea level); Exposure to High Altitude (Säntis; 2500m above sea level) for approximately 5 hours
Experimental: Order B; Firstly, the participants will exposed to High Altitude (Säntis; 2500m above sea level) and consecutively will they have assessement in Zurich (Low altitude; 470m above sea level).	Other: Assessment at Low Altitude (470m above sea level); Assessment at Low Altitude (in Zurich; 470m above sea level) in order to compare this data with High altitude exposure; Other: Exposure to High Altitude (2500m above sea level); Exposure to High Altitude (Säntis; 2500m above sea level) for approximately 5 hours

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
endurance time at High Altitude	The time of a constant loaded exercise test by an ergometer in sitting position at High Altitude will be compared with the same test at low altitude (370m above sea level)	1 day at altitude

Collaborators and Investigators

• Sponsor: University of Zurich

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2018
• Primary Completion (Actual): January 1, 2019
• Study Completion (Actual): January 1, 2019

Study Registration Dates

• First Submitted: July 9, 2018
• First Submitted That Met QC Criteria: August 16, 2018
• First Posted (Actual): August 17, 2018

Study Record Updates

• Last Update Posted (Actual): January 7, 2020
• Last Update Submitted That Met QC Criteria: January 6, 2020
• Last Verified: January 1, 2020

More Information

Terms related to this study

• Keywords: exercise capacity; High Altitude; contant loaded exercise test
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Respiratory Tract Diseases; Lung Diseases; Hypertension; Hypertension, Pulmonary
• Other Study ID Numbers: 2018-00455_B1

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No