Tolvaptan in heart failure: Contemporary evidence and a framework for precision decongestion.

Congestion remains a major therapeutic target in heart failure (HF), despite advances in guideline-directed medical therapy. Tolvaptan, a selective vasopressin V2 receptor antagonist, promotes electrolyte-sparing free-water excretion and therefore offers a mechanistically distinct approach to decongestion. Randomized trials have generally shown short-term increases in urine output and reductions in body weight, whereas effects on dyspnea and other congestion-related symptoms have been variable; importantly, no reduction in mortality or HF hospitalization has been established. This evidence has led to divergent clinical positioning: tolvaptan is approved in Japan for fluid retention inadequately controlled by other diuretics, whereas the United States and Europe do not approve it for HF congestion. This review critically summarizes the pharmacology, clinical evidence, and regional regulatory context of tolvaptan in HF. It then presents a conceptual two-stage framework incorporating potential pretreatment and early-response markers to inform patient selection, with particular attention to urine osmolality and emerging pathway-based biomarkers. The complementary roles of oral and intravenous formulations and evidence in selected clinical settings are also discussed. Current data support tolvaptan as a monitored adjunct for selected patients, not as routine therapy or a treatment with established prognostic benefit.