Effect of Breathing Oxygen-Enriched Air on Exercise Performance in Patients With Pulmonary Hypertension Due to Heart Failure With Preserved Ejection Fraction: A Randomized, Placebo-Controlled, Crossover Trial

Frontiers in Medicine

article

Julian Müller¹  Esther I. Schwarz¹  Silvia Ulrich¹  Mona Lichtblau¹  Stéphanie Saxer¹  Luigi-Riccardo Calendo¹  Arcangelo F. Carta¹  Simon R. Schneider¹  Charlotte Berlier¹  Michael Furian¹  Konrad E. Bloch¹ 

[1] Pulmonary Clinic, University Hospital Zürich;Faculty of Medicine, University of Zürich;Centre for Integrative Human Physiology, University of Zürich

关键词: pulmonary hypertension;    heart failure with preserved ejection fraction;    oxygen therapy;    exercise;    external cycling work;    cardiopulmonary exercise test;   

DOI  :  10.3389/fmed.2021.692029

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Objective: To evaluate the effects of breathing oxygen-enriched air (oxygen) on exercise performance in patients with pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF). Methods: Ten patients with PH-HFpEF (five women, age 60 ± 9 y, mPAP 37 ± 14 mmHg, PAWP 18 ± 2 mmHg, PVR 3 ± 3 WU, resting SpO 2 98 ± 2%) performed two-cycle incremental exercise tests (IET) and two constant-work-rate exercise test (CWRET) at 75% maximal work-rate ( W max ), each with ambient air (FiO 2 0.21) and oxygen (FiO 2 0.5) in a randomized, single-blinded, cross-over design. The main outcomes were the change in W max (IET) and cycling time (CWRET) with oxygen vs. air. Blood gases at rest and end-exercise, dyspnea by Borg CR10 score at end-exercise; continuous SpO 2 , minute ventilation (V'E), carbon dioxide output (V'CO 2 ), and cerebral and quadricep muscle tissue oxygenation (CTO and QMTO) were measured. Results: With oxygen vs. air, W max (IET) increased from 94 ± 36 to 99 ± 36 W, mean difference (95% CI) 5.4 (0.9–9.8) W, p = 0.025, and cycling time (CWRET) from 532 ± 203 to 680 ± 76 s, +148 (31.8–264) s, p = 0.018. At end-exercise with oxygen, Borg dyspnea score and V'E/V'CO 2 were lower, whereas PaO 2 and end-tidal PaCO 2 were higher. Other parameters were unchanged. Conclusion: Patients with PH-HFpEF not revealing resting hypoxemia significantly improved their exercise performance while breathing oxygen-enriched air along with less subjective dyspnea sensation, a better blood oxygenation, and an enhanced ventilatory efficiency. Future studies should investigate whether prolonged training with supplemental oxygen would increase the training effect and, potentially, daily activity for PH-HFpEF patients. Clinical Trial Registration: [ clinicaltrials.gov ], identifier [ {"type":"clinical-trial","attrs":{"text":"NCT04157660","term_id":"NCT04157660"}} NCT04157660 ].

【 授权许可】

CC BY