{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T20:49:24Z","timestamp":1791492564104,"version":"4.3.4"},"reference-count":36,"publisher":"Oxford University Press (OUP)","issue":"5","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001711","name":"Swiss national Science Foundation","doi-asserted-by":"publisher","award":["32003B_219199\/1"],"award-info":[{"award-number":["32003B_219199\/1"]}],"id":[{"id":"10.13039\/501100001711","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Silvia Ulrich"},{"DOI":"10.13039\/501100024099","name":"Philips Switzerland","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100024099","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Aims<\/jats:title>\n                    <jats:p>Patients with pulmonary arterial and distal chronic thromboembolic pulmonary hypertension (PAH\/CTEPH) frequently experience exertional dyspnoea with desaturation. Although ambulatory low-flow supplemental oxygen therapy (SOT) is commonly prescribed, its effect via portable concentrators in daily life has not been studied. We investigated the effect of ambulatory SOT on six-minute walk distance (6MWD).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and results<\/jats:title>\n                    <jats:p>This was a randomized non-inferiority crossover study in patients with PAH or CTEPH desaturating by &amp;gt;3% during exercise. Patients performed two 6MWD tests in randomized order: one in ambient air and one with pulsed low-flow (1\u20132\u2005L\/min) nasal supplemental oxygen (SOT) by a portable back-packed concentrator. The primary outcome was 6MWD with a predefined non-inferiority margin of \u221235\u2005m for ambient air vs. SOT. Forty patients (age 62 \u00b1 15 years, 21 female, 20 PAH, 20 CTEPH) were included. The mean difference in 6MWD between ambient air and SOT was 0\u202fm (95% CI: \u221215 to 14\u202fm, P\u202f&amp;lt;0.001).Five patients exceeded the minimal clinically important difference of 35\u2005m with SOT. At end-exercise, the cohort desaturated 2% less with SOT (95% CI \u22123 to \u22120.2%, P = 0.025) and reported 1 point less dyspnoea (95% CI 0.3 to 1, P &amp;lt; 0.002). These effects were also observed in PAH but not in CTEPH.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Walking on ambient air was non-inferior to low-flow SOT during 6MWD in treated PAH\/CTEPH patients with exercise-induced desaturation and relatively preserved exercise capacity. SOT reduced dyspnoea in PAH. Future research should identify SOT responders and develop lighter, more effective devices tailored to patient needs.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Registration<\/jats:title>\n                    <jats:p>ClinicalTrials.gov (NCT06384534)<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ehjopen\/oeag125","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T11:25:49Z","timestamp":1787570749000},"source":"Crossref","is-referenced-by-count":1,"title":["Effect of low-flow oxygen therapy on 6 minute walk test in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: a randomized non-inferiority crossover trial"],"prefix":"10.1093","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-9895-2476","authenticated-orcid":false,"given":"Carmen","family":"Wick","sequence":"first","affiliation":[{"name":"Department of Pulmonology, University 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,","place":["Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4059-5937","authenticated-orcid":false,"given":"Julian","family":"M\u00fcller","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich , R\u00e4mistrasse 100, 8091 Zurich ,","place":["Switzerland"]},{"name":"Faculty of Medicine, University of Zurich , R\u00e4mistrasse 71, 8006 Zurich ,","place":["Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-9142-7308","authenticated-orcid":false,"given":"Alessandro","family":"Vella","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich , R\u00e4mistrasse 100, 8091 Zurich ,","place":["Switzerland"]},{"name":"Faculty of Medicine, University of Zurich , R\u00e4mistrasse 71, 8006 Zurich ,","place":["Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zoe","family":"Bousraou","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich , R\u00e4mistrasse 100, 8091 Zurich ,","place":["Switzerland"]},{"name":"Faculty of Medicine, University of Zurich , R\u00e4mistrasse 71, 8006 Zurich ,","place":["Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8518-5029","authenticated-orcid":false,"given":"Michael","family":"Furian","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich , R\u00e4mistrasse 100, 8091 Zurich ,","place":["Switzerland"]},{"name":"Faculty of Medicine, University of Zurich , R\u00e4mistrasse 71, 8006 Zurich 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