P43
Effect of oxygen therapy on exercise performance in pulmonary hypertension due to HFpEF
J. Müller1, M. Lichtblau1, S. Saxer1, L. R. Calendo1, A. Carta1, S. Schneider1, K. . Bloch1, S. Ulrich1 (1Zürich)
Introduction
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).
Méthodologie
10 patients with PH-HFpEF (5 women, age 60±9 years, mPAP 37±14 mmHg, PAWP 18±2 mmHg, PVR 3±3 WU, resting SpO2 98±2 %) performed two cycle incremental exercise tests (IET) and two constant work-rate exercise test (CWRET) at 75 % maximal work-rate (Wmax) achieved with ambient air, each with ambient air (FiO2 0.21) and oxygen (FiO2 0.50) in a randomized, single-blinded, cross-over design. The main outcomes were the change in Wmax (IET) and cycling-time (CWRET) with oxygen versus air. Blood gases at rest and end-exercise, dyspnea by Borg 10 scale at end-exercise and continuous SpO2, minute ventilation (VE), carbon dioxide output (VCO2), cerebral and quadriceps muscle tissue oxygenation (CTO and MTO) were measured.
Résultats
With oxygen vs. air, Wmax increased from 94±36 to 99±36 W, mean difference (95% CI) 5.4 (0.9 to 9.8) W, p=0.025 in IET and cycling-time from 532±203 to 680±76 seconds (s), +148 (31.8 to 264) s, p=0.018. At end-exercise with oxygen, Borg dyspnea score, VE/VCO2 were lower whereas PaO2 and end-tidal CO2 were higher, other parameters were unchanged.
Discussion et conclusions
Patients with PH-HFpEF not revealing resting hypoxemia, significantly improved their exercise performance with breathing oxygen-enriched air along with less dyspnea sensation, a better blood oxygenation and an enhanced ventilatory efficiency.
Importance pour la pratique
PH-HFpEF patients may benefit from oxygen therapy during exercise training.