1. Exercise ventilatory inefficiency in heart failure and chronic obstructive pulmonary disease 
Joshua R. Smith, Erik H. Van Iterson, Bruce D. Johnson, Barry A. Borlaug, Thomas P. Olson 
International Journal of Cardiology 
Volume 274, Pages (January 2019)
DOI: /j.ijcard
Copyright © 2018 Elsevier B.V. Terms and Conditions

2. Fig. 1
V̇E/V̇CO2 slope and V̇E intercept in COPD, HFpEF, and HFrEF patients.
HFrEF patients had a greater V̇E/V̇CO2 slope compared to COPD and HFpEF patients (p < 0.01). COPD patients had a greater V̇E intercept compared to HFpEF and HFrEF patients (p < 0.01). ‡, significantly different from HFrEF patients. *, significantly different from COPD patients. Data are reported as median and 25–75 interquartile range.
International Journal of Cardiology  , DOI: ( /j.ijcard )
Copyright © 2018 Elsevier B.V. Terms and Conditions

3. Fig. 2 ROC curve analysis considering all HF and COPD patients.
The ROC curve identified a cutoff for V̇E intercept of ≥2.64 L/min to indicate patients with a high probability of having COPD (AUC: 0.88; p < 0.01).
International Journal of Cardiology  , DOI: ( /j.ijcard )
Copyright © 2018 Elsevier B.V. Terms and Conditions