Clinical Trial: Effects of Bosentan (Tracleer) in the Course of Pulmonary Artery Hypertension Induced by Hypoxia

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effects of Bosentan (Tracleer) in the Course of Pulmonary Artery Hypertension Induced by Hypoxia

Brief Summary:

Excessive rise in pulmonary artery pressure induced by low oxygen tension (hypoxia) is one of the factors implicated in high-altitude pulmonary oedema. Plasma ET1 increases in subjects exposed to high altitude and is correlated to pulmonary artery pressure.

The aim of the study is to investigate whether blockade of ET1 receptors would reduce the acute rise in systolic pulmonary artery pressure induced by hypoxia.


Detailed Summary: Patients will be examined on a variable load supine bicycle ergometer. The exercise table will be tilted laterally by 20 to 30 degrees to the left. PASP will be assessed using Doppler echocardiography at rest and during during supine bicycle exercise in NORMOXIA and hypoxia. Exposure to normobaric hypoxia will be performed by breathing a hypoxic gas mixture at sea level during 90 minutes (12,3 % O2 + 87.7 % N2) reproducing conditions at 4300 m altitude. Exercise will be started at an initial workload of 40 watts and increased by 10 watts every minute to reach a workload level defined by a heart rate (HR) corresponding to 50% of the estimated maximal aerobic power
Sponsor: Assistance Publique - Hôpitaux de Paris

Current Primary Outcome: To investigate whether bosentan compared to placebo reduces hypoxia-induced increase in pulmonary artery pressure in healthy subjects and in subjects with past history of high-altitude pulmonary oedema [ Time Frame: during the study ]

Original Primary Outcome: To investigate whether bosentan compared to placebo reduces hypoxia-induced increase in pulmonary artery pressure in healthy subjects and in subjects with past history of high-altitude pulmonary oedema

Current Secondary Outcome:

  • To compare [ Time Frame: during the study ]
  • pulmonary artery pressure response to exercise, [ Time Frame: during the study ]
  • exercise capacity, [ Time Frame: during the study ]
  • oxygen desaturation, [ Time Frame: during the study ]
  • and to assess the global safety [ Time Frame: during the study ]


Original Secondary Outcome:

  • To compare
  • - pulmonary artery pressure response to exercise,
  • - exercise capacity,
  • - oxygen desaturation,
  • and to assess the global safety


Information By: Assistance Publique - Hôpitaux de Paris

Dates:
Date Received: December 1, 2005
Date Started: January 2006
Date Completion:
Last Updated: October 16, 2008
Last Verified: March 2007