Effect of long-term oxygen therapy on exercise capacity and quality of life in exercise-desaturating patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension: a randomized-sham-controlled cross-over trial

We tested whether long-term oxygen therapy (LTOT) at home would improve exercise capacity and quality of life in exercise-desaturating patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension (PAH/CTEPH). In this randomized, sham-controlled, double-blind, cross-over trial PAH/CTEPH-patients with exercise desaturation (resting PaO2>7.3 kPa) were recruited. They received either LTOT or sham air for 5 weeks (2-3l/min via nasal cannula, during nights and daytime rest, 9-13h/day) according to a randomized cross-over design, with 2 weeks wash-out in between. Co-primary outcomes were the 6-minute walking distance (6MWD) and the SF-36 physical component summary score (PCS). 30 patients (14/16 PAH/CTEPH, age 60±15y, BMI 28±6kg/m2, 6MWD 484±117m, mPAP 39±11mmHg) pretreated with endothelin-receptor antagonists (60%) and/or phosphodiesterase-5-inhibitors (43%) were randomized. There was a significant treatment effect of oxygen on the 6MWD (figure), whereas the effect on the PCS was non-significant.