Effects of Normobaric Hypoxia During Exercise in Patients With Pulmonary Hypertension Receiving Sildenafil

Not Applicable

Completed

• Conditions: Hypertension, Pulmonary
• Interventions: Other: Normobaric hypoxia (FiO2 15%) under Sildenafil; Other: Normobaric hypoxia (FiO2 15%)

• Registration Number: NCT04697862
• Lead Sponsor: University of Zurich

Brief Summary

To study the effect of acute normobaric hypoxia during exercise in patients with pulmonary hypertension with/without Sildenafil

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-12-20
• Study First Submitted QC: 2021-01-05
• Study First Posted: 2021-01-06
• Study Start: 2021-02-01
• Status Verified: 2022-05
• Primary Completion: 2023-05-31
• Study Completion: 2023-05-31
• Last Update Submitted: 2023-06-05
• Last Update Posted: 2023-06-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 24

Inclusion Criteria

• Informed consent as documented by signature (Appendix Informed Consent Form)
• PH class I (PAH) or IV (CTEPH) diagnosed according to guidelines: mean pulmonary artery pressure >20 mmHg, pulmonary vascular resistance ≥3 wood units, pulmonary arterial wedge pressure ≤15 mmHg during baseline measures at the diagnostic right-heart catheterization

Exclusion Criteria

• resting partial pressure of oxygen <8 kilopascal at Zürich altitude on ambient air
• exposure to an altitude >1000 m for ≥3 nights during the last 2 weeks before the study
• inability to follow the procedures of the study
• patients who take nitrates
• other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Normobaric hypoxia (FiO2 15%) under Sildenafil	Normobaric hypoxia (FiO2 15%) under Sildenafil	Inhalation of deoxygenated air through an altitude simulator ("Altitrainer"), for approx. 1/2 hour. given by a facemask, first at rest and then during exercise under Sildenafil.
Normobaric hypoxia (FiO2 15%)	Normobaric hypoxia (FiO2 15%)	Inhalation of deoxygenated air through an altitude simulator ("Altitrainer"), for approx. 1/2 hour given by a facemask, first at rest and then during exercise.

Primary Outcome Measures

Name	Time	Method
mean pulmonary artery pressure (mPAP) / cardiac output (CO)	4 hours	Difference in mPAP/CO during exercise between tests under normoxia with/without Sildenafil

Secondary Outcome Measures

Name	Time	Method
Differences in cardiac output	4 hours	Differences in cardiac output at rest and during exercise with/without Sildenafil
Differences in pulmonary vascular resistance	4 hours	Differences in pulmonary vascular resistance at rest and during exercise with/without Sildenafil
Differences in pulmonary artery wedge pressure	4 hours	Differences in pulmonary artery wedge pressure at rest and during exercise with/without Sildenafil
Differences in blood pressure	4 hours	Differences in blood pressure at rest and during exercise with/without Sildenafil
Differences in mixed venous oxygen saturation	4 hours	Differences in mixed venous oxygen saturation at rest and during exercise with/without Sildenafil
Differences in oxygen saturation	4 hours	Differences in oxygen saturation at rest and during exercise with/without Sildenafil
Differences in mixed venous blood gases	4 hours	Differences in mixed venous blood gases at rest and during exercise with/without Sildenafil
Differences in pulmonary arterial pressure	4 hours	Differences in pulmonary arterial pressure at rest and during exercise with/without Sildenafil
Differences in right atrial pressure	4 hours	Differences in right atrial pressure at rest and during exercise with/without Sildenafil
Differences in heart rate	4 hours	Differences in heart rate at rest and during exercise with/without Sildenafil
Differences in arterial blood gases	4 hours	Differences in arterial blood gases at rest and during exercise with/without Sildenafil
Differences in cerebral tissue oxygenation	4 hours	Differences in cerebral tissue oxygenation at rest and during exercise with/without Sildenafil
Differences in symptoms (Borg dyspnoea)	4 hours	Differences in symptoms (Borg dyspnoea) at rest and during exercise with/without Sildenafil
Differences in muscle tissue oxygenation	4 hours	Differences in muscle tissue oxygenation at rest and during exercise with/without Sildenafil
Differences in symptoms (Borg leg effort)	4 hours	Differences in symptoms (Borg leg effort) at rest and during exercise with/without Sildenafil

Trial Locations

Locations (1)

UniversityHospital Zurich, Department of Pulmonology; 🇨🇭 Zurich, Switzerland