PT  - JOURNAL ARTICLE
AU  - Simon R. Schneider
AU  - Laura C. Mayer
AU  - Mona Lichtblau
AU  - Charlotte Berlier
AU  - Esther I. Schwarz
AU  - Stéphanie Saxer
AU  - Lu Tan
AU  - Michael Furian
AU  - Konrad E. Bloch
AU  - Silvia Ulrich
TI  - Effect of a day-trip to altitude (2500 m) on exercise performance in pulmonary hypertension: randomised crossover trial
AID  - 10.1183/23120541.00314-2021
DP  - 2021 Oct 01
TA  - ERJ Open Research
PG  - 00314-2021
VI  - 7
IP  - 4
4099  - http://openres.ersjournals.com/content/7/4/00314-2021.short
4100  - http://openres.ersjournals.com/content/7/4/00314-2021.full
SO  - erjor2021 Oct 01; 7
AB  - Question addressed by the study To investigate exercise performance and hypoxia-related health effects in patients with pulmonary hypertension (PH) during a high-altitude sojourn.Patients and methods In a randomised crossover trial in stable (same therapy for >4 weeks) patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) with resting arterial oxygen tension (PaO2) ≥7.3 kPa, we compared symptom-limited constant work-rate exercise test (CWRET) cycling time during a day-trip to 2500 m versus 470 m. Further outcomes were symptoms, oxygenation and echocardiography. For safety, patients with sustained hypoxaemia at altitude (peripheral oxygen saturation <80% for >30 min or <75% for >15 min) received oxygen therapy.Results 28 PAH/CTEPH patients (n=15/n=13); 13 females; mean±sd age 63±15 years were included. After >3 h at 2500 m versus 470 m, CWRET-time was reduced to 17±11 versus 24±9 min (mean difference −6, 95% CI −10 to −3), corresponding to −27.6% (−41.1 to −14.1; p<0.001), but similar Borg dyspnoea scale. At altitude, PaO2 was significantly lower (7.3±0.8 versus 10.4±1.5 kPa; mean difference −3.2 kPa, 95% CI −3.6 to −2.8 kPa), whereas heart rate and tricuspid regurgitation pressure gradient (TRPG) were higher (86±18 versus 71±16 beats·min−1, mean difference 15 beats·min−1, 95% CI 7 to 23 beats·min−1) and 56±25 versus 40±15 mmHg (mean difference 17 mmHg, 95% CI 9 to 24 mmHg), respectively, and remained so until end-exercise (all p<0.001). The TRPG/cardiac output slope during exercise was similar at both altitudes. Overall, three (11%) out of 28 patients received oxygen at 2500 m due to hypoxaemia.Conclusion This randomised crossover study showed that the majority of PH patients tolerate a day-trip to 2500 m well. At high versus low altitude, the mean exercise time was reduced, albeit with a high interindividual variability, and pulmonary artery pressure at rest and during exercise increased, but pressure–flow slope and dyspnoea were unchanged.Short-time exposure to high altitude in pulmonary hypertension induces hypoxaemia, reduces constant work-rate cycle time compared to ambient air and is well tolerated overall https://bit.ly/3xUAFMs