A multi-center,_double-blind,_pararel-group comparison phase 4 trial to investigate the effect of tolvaptan on mid- to long-term prognosis of heart failure patients

INTERVENTION: investigational material(s) Generic name etc : tolvaptan INN of investigational material : Therapeutic category code : 213 Diuretics Dosage and Administration for Investigational material : Once‐daily oral administration of one tolvaptan 15 mg tablet in the morning control material(s) Generic name etc : Placebo INN of investigational material : Therapeutic category code : ‐‐‐ Other Dosage and Administration for Investigational material : Once‐daily oral administration of one placebo tablet in the morning CONDITION: Volume overload in heart failure that does not respond adequately to other diuretics (e.g., loop diuretics) PRIMARY OUTCOME: mid‐ or long‐term prognosis; ; Assessment of events over 26 weeks ; ; Adverse events, serum sodium concentration, clinical laboratory tests, vital signs, 12‐lead ECG, M‐mode echocardiography, and mortality at Week 26; Change from baseline; ; Body weight, congenitive findings, cardiothoracic ratio, pulmonary congestion, New York Heart Association (NYHA) Classification, plasma brain natriuretic peptide (BNP) concentration; Change from baseline INCLUSION CRITERIA: 1) Patients from whom informed consent has been properly obtained in writing prior to start of the trial 2) Patients who have been clinically diagnosed with heart failure 3) Patients with any of the following conditions or symptoms: lower limb edema, dyspnea, jugular venous distension, hepatomegaly, pulmonary rales, third heart sound, or pulmonary congestion 4) Patients who have been receiving loop diuretics, thiazide diuretics, or anti‐aldosterone diuretics 5) Male or female patients of age 20 to 85 years inclusive (at time of informed consent) 6) Patients who, together with their partner(s), are able to use an appropriate method of contraception until 3 months after final trial drug administration 7) Patients who are able to be hospitalized at the trial site for at least 7 days from the start of trial drug administration