Dyskalemia in Heart Failure Follows the Goldilocks Principle

The medical community has an atavic fear related to hyperkalemia. This fear is based on the premise that life-saving drugs for heart failure such as renin–angiotensin–aldosterone system inhibitors (RAASi) might induce hyperkalemia. Two consequences are derived from here. First, hyperkalemia has received an inordinate amount of attention; conversely, hypokalemia has not, despite preliminary evidence suggesting that low potassium also have worse outcomes. 1 Ferreira JP Claggett BL Liu J Desai AS Pfeffer MA Anand IS et al. Serum potassium and outcomes in heart failure with preserved ejection fraction: a post-hoc analysis of the PARAGON-HF trial. Eur J Heart Fail. 2021; 23: 776-784 Crossref PubMed Scopus (10) Google Scholar , 2 Ferreira JP Mogensen UM Jhund PS Desai AS Rouleau JL Zile MR et al. Serum potassium in the PARADIGM-HF trial. Eur J Heart Fail. 2020; 22: 2056-2064 Crossref PubMed Scopus (25) Google Scholar , 3 Nunez J Bayes-Genis A Zannad F Rossignol P Nunez E Bodi V et al. Long-term potassium monitoring and dynamics in heart failure and risk of mortality. Circulation. 2018; 137: 1320-1330 Crossref PubMed Scopus (103) Google Scholar The second consequence takes place when clinicians stop RAASi in the setting of hyperkalemia, and it is impossible to distinguish whether the impaired outcome in this situation is due directly to hyperkalemia per se or to the halting of RAASi.