patients with volume overload, and that its action was not associated
with electrolyte imbalance or renal impairment.18 The
presence of worsening congestive symptoms is a leading cause
of hospitalization, and reduction in the patient’s quality of life.19
In the QUEST study, improvement of congestive symptoms was
also reported.18
However, the applicability of the results of the QUEST study
is limited by the clinical trial’s strict inclusion and exclusion
criteria for enrollment. Therefore, it is desirable to confirm
whether the efficacy and safety features of tolvaptan in clinical
trials can be extended to real-world clinical settings. Hence the
aim of this study was to provide efficacy and safety data from
post-marketing surveillance of tolvaptan in HF patients with
volume overload. Hypernatremia is a major and unique concern
with tolvaptan because of its aquaretic nature, and a risk analysis
was executed to predict the occurrence of hypernatremia
after tolvaptan treatment.