Hyperkalemia in heart failure: Foe or friend?

Hyperkalemia is a frequent and sometimes life-threatening condition that may be associated with arrhythmia and cardiac dysfunction in patients with heart failure (HF). High potassium levels in HF represent both a direct risk for cardiovascular complication and an indirect biomarker of the severity of the underlying disease, reflecting neurohormonal activation and renal dysfunction. Evaluating the prevalence and significance of hyperkalemia in HF patients is essential for optimizing the use of potassium sparing agents, such the renin-angiotensin-aldosterone system inhibitors (RAASi) or angiotensin receptor-neprilysin inhibitors and mineralocorticoid receptor antagonists, which represent a well-established cornerstone and life-saving therapy. In this review we discuss recent findings and current concepts related to the epidemiology, pathological mechanisms and implications of hyperkalemia, as well as novel therapeutic approaches to counteract it in patients with HF. The balance between optimizing life-saving potassium sparing medication and minimizing hyperkalemia-associated risk is much needed in patients with HF. Although older potassium-binding agents are associated with serious adverse events, novel potassium-binding drugs are effective in lowering potassium levels and are generally well tolerated. Novel potassium-binding drugs, such as patiromer and sodium zirconium cyclosilicate, may help to optimize therapy in HF and achieve guideline-recommended doses. Hyperkalemia is common in HF patients and is associated with a poorer prognosis and an increased risk of cardiovascular complications: Contrariwise, "moderate" potassium levels go with a better prognosis, while the emergence of new drugs, potassium binders, could allow target doses of RAASi to be achieved.