H. Ito provided a letter to the editor discussing our recently published study on electrolyte disorders in patients presenting to the emergency department with community-acquired pneumonia (CAP) [1]. Above all, H. Ito misses the discussion of heart failure as a differential diagnosis for pneumonia and criticizes a possible confounding of the association of hyponatremia with CAP in our study [2]. The impact of heart failure especially on hyponatremia is very important indeed and the clinical similarities of pneumonia and heart failure are evident.
