Commenting on "Prognostic and diagnostic significance of copeptin in acute exacerbation of chronic obstructive pulmonary disease and acute heart failure: data from ACE 2 study" by Jacob A. Winther and colleagues.

We would like to comment on the article entitled "Prognostic and diagnostic significance of copeptin in acute exacerbation of chronic obstructive pulmonary disease and acute heart failure: data from ACE 2 study" by Jacob A. Winther and colleagues, in the light of the results of a multicentric study published in 2014 by Vetrone F. et al., in which 336 patients with dyspnea were enrolled in the Emergency Departments of three University Hospitals in Italy.These two studies confirm the prognostic role of copeptin in patients with dyspnea due to heart failure but, while Winther et al. performed the copeptin measurements only at admission, Vetrone et al. evaluated the time-course of copeptin plasma concentration from the admission to the hospital discharge. The results showed a better performance of copeptin measured at discharge as prognostic biomarker compared to copeptin at hospital admission; similarly, a lower reduction or an increase in copeptin concentration from admission to discharge was a strong prognostic predictor of unfavorable outcome. In our opinion this is a very important result, opening new perspectives for the use of copeptin as prognostic marker in HF patients.