The effect of long-term oxygen therapy on 6-minute walking distance, clinical parameters and hemodynamics in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. A prospective, randomized, controlled trial (SOPHA Study)

Background Current recommendations suggest oxygen (O₂) supplementation in patients with pulmonary hypertension (PH). The effect of long-term O₂ administration is though merely investigated among these patients. Thus, the aim of this study is to investigate the effect of long term O₂ treatment in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) on exercise capacity, clinical parameters and hemodynamics.

Methods In this prospective, randomized, controlled trial, 20 patients with PAH or CTEPH under stable PH therapy experiencing O₂ desaturations at rest and/or during physical activity will be randomised to receive O₂ or standard of care (SoC) for 12 weeks. To patients receiving SoC, O₂ therapy will be offered after 12 weeks (cross over design). The primary endpoint is the change of the distance walked in 6 minutes after 12 weeks of treatment. Secondary endpoints include change in clinical parameters and hemodynamics.

Results Overall 20 patients (O₂ n=10 vs. SoC n=10) have already been randomized and 15 have completed the study. Two patients died, one patient due to SARS-CoV2 pneumonia in the oxygen arm and one due to right heart failure in the SoC arm. The O₂ therapy is so far well tolerated by all patients. Further results are expected in due course. The study is expected to be completed by the end of December 2022.

Conclusion Oxygen therapy is well tolerated. Further results are expected soon. The effect of long-term oxygen supplementation should be furtherly investigated in larger controlled-trials.

Key words oxygen, exercise capacity, pulmonary hypertension

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Publication History

Article published online:
09 March 2023