Background: Patients with heart failure with reduced ejection fraction (HFrEF) exhibit lower efficiency, dyspnea, and diminished peak oxygen uptake (VO2peak) during exercise. Dietary nitrate (NO3 −), a source of nitric oxide (NO), has improved these measures in some studies of other populations. We determined the effects of acute NO3 − ingestion on exercise responses in 8 patients with HFrEF using a randomized, double-blind, placebo-controlled, crossover design. Methods and Results: Plasma NO3 −, nitrite (NO2 −), and breath NO were measured at multiple time points and respiratory gas exchange was determined during exercise after ingestion of beetroot juice containing or devoid of 11.2 mmol of NO3 −. NO3 − intake increased (P <.05–0.001) plasma NO3 − and NO2 − and breath NO by 1469 ± 245%, 105 ± 34%, and 60 ± 18%, respectively. Efficiency and ventilation during exercise were unchanged. However, NO3 − ingestion increased (P <.05) VO2peak by 8 ± 2% (ie, from 21.4 ± 2.1 to 23.0 ± 2.3 mL.min−1.kg−1). Time to fatigue improved (P <.05) by 7 ± 3 % (ie, from 582 ± 84 to 612 ± 81 seconds). Conclusions: Acute dietary NO3 − intake increases VO2peak and performance in patients with HFrEF. These data, in conjunction with our recent data demonstrating that dietary NO3 − also improves muscle contractile function, suggest that dietary NO3 − supplementation may be a valuable means of enhancing exercise capacity in this population.
- Nitric oxide
- heart failure