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

Abstract

Study questionWe investigated whether domiciliary oxygen therapy (DOXT) increases exercise capacity and quality of life in patients with pulmonary arterial or distal chronic thromboembolic pulmonary hypertension (PAH/CTEPH) presenting with mild resting hypoxaemia and exercise-induced oxygen desaturation.Materials and methods30 patients with PAH/CTEPH, mean±sdage 60±15 years, pulmonary artery pressure 39±11 mmHg, resting arterial oxygen saturation measured by pulse oximetry (SpO2) ≥90%,SpO2drop during a 6-min walk test ≥4%, on pulmonary hypertension-targeted medication, were randomised in a double-blind crossover protocol to DOXT and placebo (ambient air) treatment, each over 5 weeks, at 3 L·min−1vianasal cannula overnight and when resting during the day. Treatment periods were separated by 2 weeks of washout. Co-primary outcomes were changes in 6-min walk distance (6MWD, breathing ambient air) and physical functioning scale of the 36-item short-form medical outcome questionnaire during treatment periods.ResultsDOXT increased the 6MWD from baseline 478±113 m by a mean (95% CI) of 19 (6–32) m, and physical functioning from 52±29 by 4 (0–8) points. Corresponding changes with placebo were 1 (−11–13) m in 6MWD and −2 (−6–2) points in physical functioning. Between-treatment differences in changes were 6MWD 18 (1–35) m (p=0.042) and physical functioning 6 (1–11) points (p=0.029). DOXT significantly improved the New York Heart Association functional classversusplacebo.Answer to the questionThis first randomised trial in PAH/CTEPH patients with exercise-induced hypoxaemia demonstrates that DOXT improves exercise capacity, quality of life and functional class. The results support large long-term randomised trials of DOXT in PAH/CTEPH.

Current and future treatments of pulmonary arterial hypertension

“…Treatment of PAH currently includes supportive therapy such as diuretics, supervised rehabilitation, birth control advice, and oxygen supplementation, if needed (Ulrich et al, 2019). Pharmacological therapies targeting the pulmonary vasculature are currently only approved for patients with PAH (Group 1) and selected patients with CTEPH (Group 4).…”

Aktuelle Definition und Diagnostik der pulmonalen Hypertonie

“…Eine Hypoxämie scheint bei PH-Patienten insbesondere im Schlaf häufig aufzutreten [42], eine schwere Ausprägung sollte an Lungenerkrankungen und Shuntvitien denken lassen. Eine Sauerstofftherapie kann die Belastbarkeit bei PAH und CTEPH verbessern [43,44], ein eventueller prognostischer Effekt ist jedoch bisher nicht belegt.…”

Assessment of oxygenation after balloon pulmonary angioplasty for patients with inoperable chronic thromboembolic pulmonary hypertension

“…Daytime SpO 2 measurements at rest could underestimate the existence of exertional or nocturnal hypoxia after BPA [35] which may impair not only patients' quality of life but also their clinical condition. Domiciliary oxygen therapy can improve exercise capacity, quality of life, and functional class in CTEPH patients with exercise-induced hypoxemia in a randomized trial [38]. A nocturnal oximetry test, or 6-MWT should be considered as part of the routine evaluation after BPA, and domiciliary oxygen therapy or nocturnal oxygen therapy should be continued, if necessary.…”