Domiciliary Oxygen Therapy Improves Sub-Maximal Exercise Capacity and Quality of Life in Chronic Heart Failure

IntroductionA high prevalence of nocturnal hypoxia is noted in patients with chronic heart failure (CHF). Nocturnal hypoxia can be reversed by nasal oxygen or non-invasive assisted ventilation. However, controversy exists over the use of oxygen in CHF.We studied the effects of nocturnal nasal oxygen in CHF to demonstrate its effects on 6-min walk test, quality of life (QOL), NTproBNP, and echocardiographic parameters.MethodologyTen patients aged 70 ± 9 years received domiciliary oxygen (4 l/min) for one month. Oxygen was administered for a minimum of 8 h every night via nasal prongs.ResultsA 17% improvement was seen in the 6-min walk test, 298 ± 98 m to 351 ± 100 m (p = 0.005) and a 27% improvement in the QOL, which improved from 26 ± 12 to 19 ± 7 (p = 0.017). Acquired echocardiographic measures including ejection fraction, pulmonary pressure and diastolic parameters did not change.ConclusionNocturnal nasal oxygen has a significant impact on sub-maximal exercise capacity and QOL in CHF. Although a previous study has demonstrated harmful haemodynamic effects of acute oxygen administration in CHF; we did not detect any change in echocardiographic parameters using current two-dimensional imaging and Doppler studies. The lack of improvement in cardiac parameters suggests a peripheral mode of action.