|
1000
|
Abstract/Summary
|
-
<jats:p><jats:bold>Objective:</jats:bold> 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).</jats:p><jats:p><jats:bold>Methods:</jats:bold> 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<jats:sub>2</jats:sub> 98 ± 2%) performed two-cycle incremental exercise tests (IET) and two constant-work-rate exercise test (CWRET) at 75% maximal work-rate (<jats:italic>W</jats:italic><jats:sub>max</jats:sub>), each with ambient air (FiO<jats:sub>2</jats:sub> 0.21) and oxygen (FiO<jats:sub>2</jats:sub> 0.5) in a randomized, single-blinded, cross-over design. The main outcomes were the change in <jats:italic>W</jats:italic><jats:sub>max</jats:sub> (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<jats:sub>2</jats:sub>, minute ventilation (V'E), carbon dioxide output (V'CO<jats:sub>2</jats:sub>), and cerebral and quadricep muscle tissue oxygenation (CTO and QMTO) were measured.</jats:p><jats:p><jats:bold>Results:</jats:bold> With oxygen vs. air, <jats:italic>W</jats:italic><jats:sub>max</jats:sub> (IET) increased from 94 ± 36 to 99 ± 36 W, mean difference (95% CI) 5.4 (0.9–9.8) W, <jats:italic>p</jats:italic> = 0.025, and cycling time (CWRET) from 532 ± 203 to 680 ± 76 s, +148 (31.8–264) s, <jats:italic>p</jats:italic> = 0.018. At end-exercise with oxygen, Borg dyspnea score and V'E/V'CO<jats:sub>2</jats:sub> were lower, whereas PaO<jats:sub>2</jats:sub> and end-tidal PaCO<jats:sub>2</jats:sub> were higher. Other parameters were unchanged.</jats:p><jats:p><jats:bold>Conclusion:</jats:bold> 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.</jats:p><jats:p><jats:bold>Clinical Trial Registration:</jats:bold> [<jats:ext-link>clinicaltrials.gov</jats:ext-link>], identifier [NCT04157660].</jats:p>
|
