Effect of a day-trip to altitude (2500 m) on exercise performance in pulmonary hypertension: randomised crossover trial

• Published in: ERJ open research Vol. 7; no. 4; p. 314
• Main Authors: Schneider, Simon R, Mayer, Laura C, Lichtblau, Mona, Berlier, Charlotte, Schwarz, Esther I, Saxer, Stéphanie, Tan, Lu, Furian, Michael, Bloch, Konrad E, Ulrich, Silvia
• Format: Journal Article
• Language: English
• Published: England European Respiratory Society 01.10.2021
• Subjects: Original s
• ISSN: 2312-0541; 2312-0541
• DOI: 10.1183/23120541.00314-2021

To investigate exercise performance and hypoxia-related health effects in patients with pulmonary hypertension (PH) during a high-altitude sojourn. 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 ( ) ≥7.3 kPa, we compared symptom-limited constant work-rate exercise test (CWRET) cycling time during a day-trip to 2500 m 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. 28 PAH/CTEPH patients (n=15/n=13); 13 females; mean±sd age 63±15 years were included. After >3 h at 2500 m 470 m, CWRET-time was reduced to 17±11 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, was significantly lower (7.3±0.8 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 71±16 beats·min , mean difference 15 beats·min , 95% CI 7 to 23 beats·min ) and 56±25 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. This randomised crossover study showed that the majority of PH patients tolerate a day-trip to 2500 m well. At high 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.