Hyponatremia in acute decompensated heart failure: mechanisms, prognosis, and treatment options

Hyponatremia is common and is increasingly recognized as an independent prognostic marker that adversely affects morbidity and mortality in various disease states, including heart failure. In acute decompensated heart failure (ADHF), the degree of hyponatremia often parallels the severity of cardiac dysfunction and is further exacerbated by any reduction in glomerular filtration rate and arginine vasopressin dysregulation. A recent study showed that even modest improvement of hyponatremia may have survival benefits. Although management of hyponatremia in ADHF has traditionally focused on improving cardiac function and fluid restriction, the magnitude of improvement of serum sodium is fairly slow and unpredictable. In this article, we discuss the mechanisms of hyponatremia in ADHF, review its evolving prognostic significance, and evaluate the efficacy of various treatments for hyponatremia, including the recently approved vasopressin receptor antagonists for managing hyponatremia among patients hospitalized for ADHF.