Background: Patients admitted with acute decompensated heart failure (ADHF) have a poor prognosis and poor quality of life due to dyspnea and edema. Tolvaptan, a vasopressin V2 receptor antagonist, is an effective water diuretic. This study aimed to evaluate the efficacy and safety of a short course of tolvaptan to treat volume overload in patients with ADHF.

Methods: We conducted a phase III, multicenter, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of a short course of tolvaptan (15 mg/day for 4 days) in hospitalized ADHF patients with volume overload despite the use of conventional diuretics. The primary end-point was the change in body weight after 4 days of treatment. The secondary end-points were the change in intake/output balance, change in serum sodium/potassium concentrations, physician/patient assessed signs and symptoms of heart failure after 4 days of treatment, and all-cause mortality in 1 month.

Results: A total of 110 patients were screened, and 91 were randomized to receive 15 mg/day of tolvaptan for 4 days (n = 46) or matching placebo (n = 45). Compared to the placebo-treated patients, tolvaptan significantly reduced body weight (-1.36 ± 2.13 kg in the tolvaptan group vs. -0.59 ± 1.27 kg in the placebo group, p = 0.0394). The tolvaptan group also had a negative intake/urine volume balance compared to the placebo group (-509.3 ± 2788.2 ml vs. 975.5 ± 1903.1 ml, p = 0.0059). The safety profile of tolvaptan was acceptable.

Conclusion: Tolvaptan significantly reduced volume overload in hospitalized ADHF patients with volume overload despite the use of conventional diuretics.