Hyponatremia in acute heart failure syndromes: a potential therapeutic target.

Mild hyponatremia is common in patients hospitalized for worsening heart failure, and it is a major predictor of post-discharge mortality and morbidity irrespective of left ventricular ejection fraction. Recent data also suggest that standard therapy for heart failure does not improve or normalize serum sodium concentration during hospitalization. There are conclusive data that vasopressin antagonists improve or normalize serum sodium in this patient population. However, it is not known if this improvement or normalization in serum sodium is associated with an improvement in post-discharge outcomes. Future trials with vasopressin antagonists in patients hospitalized with worsening heart failure and hyponatremia are in order.