Highlanders With High Altitude Pulmonary Hypertension (HAPH), Pulmonary Arterial Pressure (PAP) Assessed at 3200m With and Without Supplemental Oxygen Therapy (SOT)

Effect of Supplemental Oxygen Therapy (SOT) on Pulmonary Arterial Pressure in Highlanders With High Altitude Pulmonary Hypertension Permanently Living at >2500m

The investigators aim to study the effect of SOT in highlanders with high altitude pulmonary hypertension (HAPH) who permanently live >2500m on pulmonary arterial pressure (PAP) assessed at 3200 m.

Study Overview

• Status: Completed
• Conditions: High Altitude Pulmonary Hypertension
• Intervention / Treatment: Other: Echocardiography

Detailed Description

Highlanders with HAPH diagnosed by echocardiography and defined by a RV/RA (Tricuspid Regurgitation Pressure Gradient) >30 mmHg will be recruited for this project. Highlanders permanently living at HA >2500 m will have echocardiografy to assess PAP near their living altitude in Aksay at 3200 m with and without 10L/min supplemental oxygen therapy (SOT) via face mask.

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Kyrgyzstan
  • Aksay Plateau, Naryn, Kyrgyzstan, Kyrgyzstan
    • Aksay Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Permanently living >2500 m
• HAPH diagnosed with a minimum RV/RA of 30 mmHg assessed by echocardiography at an altitude of 3200 m
• Written informed consent

Exclusion Criteria:

• Highlanders who cannot follow the study investigations,
• Patients with moderate to severe concomitant lung disease (FEV1<70% or forced vital capacity <70%), severe parenchymal lung disease, heavy smoking >20 cigarettes/day or >20 pack-years.
• Coexistent unstable systemic hypertension or coronary artery disease that required adjustment of medication within the last 2 months
• Regular use of medication that affects control of breathing (benzodiazepines, opioids, acetazolamide)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Ambient air; Highlanders with HAPH will perform the echocardiography on ambient air at 3200m	Other: Echocardiography; Echocardiography will be performed according to clinical standards
Experimental: 10 L/min SOT through face mask; Supplemental oxygen therapy (SOT) at 10 L/min will be provided via face mask from oxygen concentrators	Other: Echocardiography; Echocardiography will be performed according to clinical standards

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Pulmonary Artery Pressure with SOT vs.ambient air at 3200m	Change in RV/RA in mmHg assessed by echocardiography with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Cardiac Output with SOT vs. ambient air at 3200m	Change in cardiac output (l/min) assessed by echocardiography with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in right to left heart diameter ratio with SOT vs.ambient air at 3200m	Change in right to left heart diameter ratio assessed by echocardiography with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in tricuspid annular plane systolic excursion (TAPSE) with SOT vs.ambient air at 3200m	Change in tricuspid annular plane systolic excursion (TAPSE) with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in right atrial area with SOT vs. ambient air at 3200m	Change in right atrial area by echocardiography with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in right heart strain with SOT vs. ambient air at 3200m	Change in right heart strain by echocardiography with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in pH by arterial blood gases with SOT vs. ambient air at 3200m	Changes in pH by arterial blood gases with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in PaO2 by arterial blood gases with SOT vs. ambient air at 3200m	Changes in PaO2 by arterial blood gases with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen
Change in PaCO2 by arterial blood gases with SOT vs. ambient air at 3200m	Changes in PaCO2 by arterial blood gases with SOT compared to ambient air at 3200m	at 15 min of breathing ambient air or supplemental oxygen

Collaborators and Investigators

• Sponsor: University of Zurich
• Investigators: Principal Investigator: Silvia Ulrich, Prof. Dr., University Hospital Zurich, Department of Pulmonology; Principal Investigator: Talant MA Sooronbaev, Prof. Dr., National Center of Cardiology and Internal Medicine named after academician M.Mirrakhimov

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2024
• Primary Completion (Actual): December 31, 2024
• Study Completion (Actual): December 31, 2024

Study Registration Dates

• First Submitted: June 28, 2024
• First Submitted That Met QC Criteria: June 28, 2024
• First Posted (Actual): July 8, 2024

Study Record Updates

• Last Update Posted (Estimated): December 4, 2025
• Last Update Submitted That Met QC Criteria: November 26, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Pulmonary Hypertension; Hypoxia; High Altitude; Supplemental Oxygen Therapy; Pulmonal Arterial Pressure
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Hypertension; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia; Hypertension, Pulmonary; Altitude Sickness; Pulmonary edema of mountaineers
• Other Study ID Numbers: HAPH_SOT_PAP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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