Clinical Course of Patients With Hyponatremia and Decompensated Systolic Heart Failure and the Effect of Vasopressin Receptor Antagonism With Tolvaptan

Abstract

Background

Patients with decompensated heart failure, volume overload, and hyponatremia are challenging to manage. Relatively little has been documented regarding the clinical course of these patients during standard in-hospital management or with vasopressin antagonism.

Methods and Results

The Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan database was examined to assess the short-term clinical course of patients hospitalized with heart failure and hyponatremia and the effect of tolvaptan on outcomes. In the placebo group, patients with hyponatremia (serum Na⁺ <135mEq/L; n = 232), compared with those with normonatremia at baseline (n = 1785), had less relief of dyspnea despite receiving higher doses of diuretics (59.2% vs 69.2% improved; P < .01) and worse long-term outcomes. In the hyponatremia subgroup from the entire trial cohort (n = 475), tolvaptan was associated with greater likelihood of normalization of serum sodium than placebo (58% vs 20% and 64% vs 29% for day 1 and discharge, respectively; P < .001 for both comparisons), greater weight reduction at day 1 and discharge (0.7 kg and 0.8 kg differences, respectively; P < .001 and P = .008), and greater relief of dyspnea (P = .03). Among all hyponatremic patients, there was no effect of tolvaptan on long-term outcomes compared with placebo. In patients with pronounced hyponatremia (<130 mEq/L; n = 92), tolvaptan was associated with reduced cardiovascular morbidity and mortality after discharge (P = .04).

Conclusions

In patients with decompensated heart failure and hyponatremia, standard therapy is associated with less weight loss and dyspnea relief, and unfavorable longer-term outcomes compared to those with normonatremia. Tolvaptan is associated with more favorable in-hospital effects and, possibly, long-term outcomes in patients with severe hyponatremia.