Article

The-oxygen uptake efficiency slope (OUES) is a new submaximal parameter which objectively predicts the maximal exercise capacity in children and healthy subjects. However, the usefulness of OUES in adult patients with and without advanced heart failure remains undetermined. The present study investigates the stability and the usefulness of OUES in adult cardiac patients with and without heart failure. Methods Forty-five patients with advanced heart failure (group A) and 35 patients with ischemic heart disease but normal left ventricular ejection fraction (group B) performed a maximal exercise test. PeakV02 and percentage of predicted peakVO(2) were markers of maximal exercise capacity, whereas OUES, ventilatory anaerobic threshold (VAT), and slope V.E/VCO2 were calculated as parameters of submaximal exercise. Results Group A patients had lower peakVO(2) (P < -001), lower percentage of predicted peakVO(2) (P = -001), lower VAT (P <.05), steeper slope VE/VCO2 (P <.001), and lower OUES (P <.02). Within group A, significant differences were found for VAT, slope VE/VCO2, and OUES (all P <.01) between patients with peakVO(2) above and below 14 mL O-2/kg/min. Of all the submaximal parameters, VAT correlated best with peakVO(2) (r =.814, P <.01) followed by OUES/kg (r =.781, P <.01), and slope VE/VCO2 (r = -.492, P <.001). However, VAT could not be determined in 18 (23%) patients. Conclusions OUES remains stable over the entire exercise duration and is significantly correlated with peakVO(2) in adult cardiac patients with and without impaired LVEF. Therefore, OUES could be helpful to assess exercise performance in advanced heart failure patients unable to perform a maximal exercise test. Further studies are needed to confirm our hypothesis.

Langue : ANGLAIS

Tiré à part : OUI