Patients with pulmonary arterial hypertension (PAH) or distal chronic thromboembolic pulmonary hypertension (CTEPH) were able to increase 6-minute walk distance (6MWD) and improve physical status on domiciliary oxygen therapy, according to the results of a study published in the European Respiratory Journal.
This double-blind cross-over protocol evaluated 6MWD and the physical functioning scale of the Short Form Medical Outcome Questionnaire-36 in patients with PAH or distal CTEPH with exercise-induced hypoxemia. Measurements were taken at baseline and following random assignment to 1 of 2 groups: domiciliary oxygen therapy or ambient air placebo. There was a 2-week washout between treatments. Results from domiciliary oxygen therapy and ambient air placebo therapy were compared between groups.
Of the 30 patients who were randomly assigned and represented the intention-to-treat population, 2 patients withdrew consent after randomization. The per-protocol analysis included 28 patients who completed the entire protocol. From baseline, domiciliary oxygen therapy increased 6MWD an average of 19 meters vs 1 meter in the placebo group. Changes in the physical functioning scale were 4 points and -2 points for the treatment and placebo groups, respectively. Between-treatment differences in changes were 6MWD 18 meters (1-35 m; P =.042) and 6 points in the physical functioning scale of Short Form Medical Outcome Questionnaire-36 (95% CI, 1-11; P =.029).
“This first randomized trial in PAH/CTEPH patients with exercise-induced hypoxemia demonstrates that [domiciliary oxygen therapy] improves exercise capacity, quality of life and functional class,” the authors wrote. “The results support large long-term randomized trial[s] of domiciliary oxygen therapy in PAH/CTPEH.”
Ulrich S, Saxer S, Hasler ED, et al. Effect of domiciliary oxygen therapy on exercise capacity and quality of life in patients with pulmonary arterial or chronic thromboembolic pulmonary hypertension: a randomised, placebo-controlled trial [published online May 9, 2019]. Eur Respir J. doi:10.1183/13993003.002762019