Resumen de Oxygen Uptake Efficiency Slope, Aerobic Fitness, and V?E�V?CO2 Slope in Heart Failure
Sophie Antoine-Jonville, Aurélien Pichon, Ali Vazir, Michael Iain Polkey, Mark J. Dayer
Purpose: The oxygen uptake efficiency slope (OUES) is a promising submaximal index of exercise capacity, but its relationships to other indices characterizing physical fitness and ventilatory efficiency have not been widely investigated in heart failure.
Methods: Sixty-three male patients with stable chronic heart failure performed a symptom-limited maximal exercise test on a cycle ergometer. Nineteen of them performed two exercise tests, 6 months apart. The peak oxygen uptake (V?O2peak), ventilatory anaerobic threshold (VAT), OUES using all data (OUES100) or only the data up to the point where the RER was 1 (OUESRER1), and V?E�V?CO2 slope were determined.
Results: OUES100, OUESRER1, and VAT were significantly correlated with measured V?O2peak (r = 0.883, r = 0.814, and r = 0.877, respectively). The Bland�Altman limits of agreement between measured V?O2peak and the values predicted by calculation from OUES100, OUESRER1, and VAT were ±0.46, ±0.57, and ±0.48 L·min-1, respectively. The variation in OUESRER1 between the first and second tests in the 19 patients was significantly related to the variation in V?O2peak but not to the variation in the V?E�V?CO2 slope.
Conclusions: To predict V?O2peak in patients with chronic heart failure, the index OUESRER1 is not better than the VAT. This, however, does not question the theoretical interest of its calculation because it may provide additional information on the oxygen uptake limitation steps.
