We read with great interest the manuscript by Suzuki et al. investigating the prognostic impact of changes of serum potassium levels during index hospitalization in a large cohort of 1280 patients hospitalized for heart failure (HF)[1]. The authors demonstrated more advanced HF, reflected by higher New York Heart Association (NYHA) functional class and B-type natriuretic peptide levels (BNP), as well as impaired renal function were predictors for changes of serum potassium levels in HF patients.
