Abnormalities of the Ventilatory Equivalent for Carbon Dioxide in Patients with Chronic Heart Failure

Figure 3

Receiver operating characteristic curve showing value of VEqCO₂ nadir, time to VEqCO₂ nadir, and peak oxygen uptake for predicting all-cause mortality at 12 months. VEqCO₂ nadir: AUC=0.81; 𝑃<0.0001; 95% CI = 0.74–0.89; sensitivity = 86; specificity = 62; optimal cut-point = 33; time to VEqCO₂ nadir: AUC=0.75; 𝑃<0.0001; 95% CI = 0.67–0.84; sensitivity = 81; specificity = 62; optimal cut-point = 250 s; peak VO₂: AUC = 0.76; 𝑃<0.0001; 95% CI = 0.67–0.85; sensitivity = 86; specificity = 57; optimal cut-point = 20 mL·kg⁻¹·min⁻¹.