Lung TransplantationNCT07479511
Adaptation of Lung Transplant Recipients at Extreme Altitude
An observational study of Lung Transplantation and Hypoxia, run by Medical University of Vienna at 1 site in Austria.
Trial summary
This prospective observational study investigates the effects of intermittent hypoxic conditioning and real high-altitude exposure in lung transplant recipients compared with healthy controls. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Lung Transplantation, Hypoxia, Altitude
- How many people
- 30 participants
- Where
- 1 siteAustria
- Study dates
- 10 Jan 2026to 30 Jun 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Lung transplant recipients and Healthy controls
Who may be able to join
- Lung transplant recipients:
- Age ≥ 18 years
- > 1 years after lung transplantation
- Stable lung function over 6 month prior to inclusion, FEV1 +/-10% from baseline
- VO2peak of more than 25 ml/min/kg
- Physical and mental fitness, defined as the ability to complete strenuous day trips lasting 8 to 10 hours independently without suffering from a fear of heights, an altitude exposure of at least 2500m must be confirmed.
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- Negative pregnancy test for women of childbearing age
- Written informed consent
- Healthy volunteers:
- Age ≥ 18 years
- VO2peak of more than 25 ml/min/kg
- Physical and mental fitness, defined as the ability to complete strenuous day trips lasting 8 to 10 hours independently without suffering from a fear of heights
- Negative pregnancy test for women of childbearing age
- Written informed consent
Who cannot join
- Lung transplant recipients:
- Age < 18 years
- Refusal to participate in the study
- Pregnancy
- Healthy controls:
- Age < 18 years
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- Refusal to participate in the study
- Pregnancy
- Chronic obstructive pulmonary disease (COPD)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessment of Pulmonary Function and Physiological Adaptation of Lung Transplant Recipients at Extreme Altitude: The Mount Aconcagua (6971 m) Expedition
This prospective observational study investigates the effects of intermittent hypoxic conditioning and real high-altitude exposure in lung transplant recipients compared with healthy controls.
The study includes an eight-week home-based preparatory phase during which participants use a normobaric hypoxic tent with reduced oxygen concentration. Prior to this phase, all participants receive standardized training on the safe use of the equipment. During the preparatory period, daily vital parameters, including heart rate, oxygen saturation, and heart rate variability, are recorded using a sports watch and a pulse oximeter. Symptoms, adverse events, and subjective well-being are documented daily in an electronic diary. All data are transmitted to the study team via encrypted electronic systems, allowing continuous remote monitoring. At the end of the preparatory phase, participants undergo a clinical evaluation to confirm fitness for the expedition phase.
Read more
The expedition phase consists of a monitored ascent of Aconcagua (6,971 meters). Before departure, all participants are required to attend a comprehensive safety, protection, and first aid training conducted jointly by the study team and professional expedition providers. The expedition is planned and led by an experienced international expedition company in cooperation with a local provider specializing in high-altitude mountaineering.
The expedition includes arrival in Mendoza, preparatory procedures such as equipment checks and permits, followed by a staged ascent to base camp. Subsequent days involve rest periods and acclimatization hikes with the establishment of progressively higher camps. A summit attempt is planned after sufficient acclimatization, followed by descent to high camp. A weather-dependent buffer period is included before the final descent to the valley and return to Mendoza, where the expedition concludes.
Total study participation is expected to last approximately 15 weeks, including about eight weeks of home-based preparation and approximately three weeks at altitude. A final follow-up examination is conducted 2 to 4 weeks after completion of the expedition, marking the end of study participation.
- Conditions
- Lung Transplantation, Hypoxia, Altitude, High-altitude Adaptation, Immunosuppression, Physical Fitness
- Medical subject headings
- Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Lung transplant recipients | Not described | |
| Healthy volunteers | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in forced expiratory volume in one second (FEV₁)
Measured: From enrollment to the end of the expedition at 3 weeks
Change in peripheral oxygen saturation (SpO₂) as a marker of physiological adaptation
Measured: From enrollment to the end of the expedition at 3 weeks
Secondary outcomes (12)
Heart Rate Variability (HRV)
Measured: From enrollment to the end of the expedition at 3 weeks
Blood gas analysis (BGA)
Measured: From enrollment to the end of the expedition at 3 weeks
Acute mountain sickness (AMS)
Measured: From enrollment to the end of the expedition at 3 weeks
Level of immunosuppression
Measured: From enrollment to the end of the expedition at 3 weeks
Level of Torque Teno Virus (TTV)
Measured: Before enrollment until approx. 4 weeks after the end of the expedition
Voice analysis
Voice-based heart failure detection developed by Noah Labs uses artificial intelligence to analyze short voice recordings from patients with heart failure. Patients regularly record a standardized speech sample using a smartphone. Deep-learning algorithms extract numerous acoustic features such as frequency patterns and subtle variations in vocal cord vibration. The system identifies these changes as "voice biomarkers" and compares them with previous recordings. If patterns suggest worsening heart failure, clinicians can be alerted early, potentially allowing timely therapeutic adjustments and preventing hospitalizations. The study aims to investigate changes in height and in patients following lung transplantation.
Measured: Prior to enrollment to the end of the expedition at 3 weeks
Gut Microbiota Dynamics
The composition of the gut microbiota is being studied longitudinally using stool samples collected prior to the expedition and following successive ascents to high altitudes over the course of several weeks. The samples are analyzed to determine bacterial diversity and taxonomic composition. Microbial diversity indices, including Shannon, Simpson, and Chao1, are calculated to assess changes in community structure. In addition, the Bray-Curtis distance and the Jaccard index are used to assess differences in species distribution across time points. The relative abundance of bacterial taxa is quantified to identify shifts in pathogenic and beneficial microbial populations during altitude exposure.
Measured: Prior to enrollment to the end of the expedition at 3 weeks
Transthoracic echocardiography
Measured: Prior to enrollment to the end of the expedition at 3 weeks
Lung Ultrasound Score
Measured: Prior to enrollment to the end of the expedition at 3 weeks
Renin-angiotensin-aldosterone system
Measured: Prior to enrollment to the end of the expedition at 3 weeks
End-tidal CO₂ measurements
Measured: Prior to enrollment to the end of the expedition at 3 weeks
Continuous glucose monitoring
Measured: Prior to enrollment to the end of the expedition at 3 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2026
- Study start10 Jan 2026
- Primary completion30 May 2026 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Lung TransplantationStudies of the same condition, open and under way.
- More trials run by Medical University of ViennaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jakob Mühlbacher, MD, Medical University of Vienna
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07479511
- Sponsor's protocol ID
- 2105/2025
- Other IDs
- EK Nr: 2105/2025
- Status last verified
- Mar 2026
- First submitted
- 19 Jan 2026
- Last updated
- 18 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Pulmonary Function and Physiological Adaptation of Lung Transplant Recipients at Extreme Altitude: The Mount Aconcagua (6971 m) Expedition
- ClinicalTrials.gov ID
- NCT07479511
- Acronym / sponsor ID
- 2105/2025
- Conditions
- Lung Transplantation, Hypoxia, Altitude, High-altitude Adaptation, Immunosuppression, Physical Fitness
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- 10 Jan 2026 (actual)
- Primary completion
- 30 May 2026 (estimated)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 18 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective observational study investigates the effects of intermittent hypoxic conditioning and real high-altitude exposure in lung transplant recipients compared with healthy controls.
The study includes an eight-week home-based preparatory phase during which participants use a normobaric hypoxic tent with reduced oxygen concentration. Prior to this phase, all participants receive standardized training on the safe use of the equipment. During the preparatory period, daily vital parameters, including heart rate, oxygen saturation, and heart rate variability, are recorded using a sports watch and a pulse oximeter. Symptoms, adverse events, and subjective well-being are documented daily in an electronic diary. All data are transmitted to the study team via encrypted electronic systems, allowing continuous remote monitoring. At the end of the preparatory phase, participants undergo a clinical evaluation to confirm fitness for the expedition phase.
The expedition phase consists of a monitored ascent of Aconcagua (6,971 meters). Before departure, all participants are required to attend a comprehensive safety, protection, and first aid training conducted jointly by the study team and professional expedition providers. The expedition is planned and led by an experienced international expedition company in cooperation with a local provider specializing in high-altitude mountaineering.
The expedition includes arrival in Mendoza, preparatory procedures such as equipment checks and permits, followed by a staged ascent to base camp. Subsequent days involve rest periods and acclimatization hikes with the establishment of progressively higher camps. A summit attempt is planned after sufficient acclimatization, followed by descent to high camp. A weather-dependent buffer period is included before the final descent to the valley and return to Mendoza, where the expedition concludes.
Total study participation is expected to last approximately 15 weeks, including about eight weeks of home-based preparation and approximately three weeks at altitude. A final follow-up examination is conducted 2 to 4 weeks after completion of the expedition, marking the end of study participation.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Lung transplant recipients | – | – |
| Healthy volunteers | – | – |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Lung transplant recipients and Healthy controls
Key inclusion criteria (14 listed)
- Age ≥ 18 years
- > 1 years after lung transplantation
- Stable lung function over 6 month prior to inclusion, FEV1 +/-10% from baseline
- VO2peak of more than 25 ml/min/kg
- Physical and mental fitness, defined as the ability to complete strenuous day trips lasting 8 to 10 hours independently without suffering from a fear of heights, an altitude exposure of at least 2500m must be confirmed.
Key exclusion criteria (9 listed)
- Age < 18 years
- Refusal to participate in the study
- Pregnancy
- Age < 18 years
- Refusal to participate in the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in forced expiratory volume in one second (FEV₁)
Time frame: From enrollment to the end of the expedition at 3 weeks
Change in peripheral oxygen saturation (SpO₂) as a marker of physiological adaptation
Time frame: From enrollment to the end of the expedition at 3 weeks
12 secondary outcomes
Heart Rate Variability (HRV)
Time frame: From enrollment to the end of the expedition at 3 weeks
Blood gas analysis (BGA)
Time frame: From enrollment to the end of the expedition at 3 weeks
Acute mountain sickness (AMS)
Time frame: From enrollment to the end of the expedition at 3 weeks
Level of immunosuppression
Time frame: From enrollment to the end of the expedition at 3 weeks
Level of Torque Teno Virus (TTV)
Time frame: Before enrollment until approx. 4 weeks after the end of the expedition
Voice analysis
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
Gut Microbiota Dynamics
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
Transthoracic echocardiography
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
Lung Ultrasound Score
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
Renin-angiotensin-aldosterone system
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
End-tidal CO₂ measurements
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
Continuous glucose monitoring
Time frame: Prior to enrollment to the end of the expedition at 3 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Mar 2026.
- Description of the project and the expeditionLink provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Lung Transplantation and Hypoxia, run by Medical University of Vienna at 1 site in Austria.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 18 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in forced expiratory volume in one second (FEV₁) (time frame: From enrollment to the end of the expedition at 3 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Mar 2026.