An open-label, prospective randomized trial to assess the non-inferiority of diuretic effect of tolvaptan as an alternative agent to loop diuretics in chronic heart failure

INTERVENTION: Intervention group: Patients in whom furosemide of 20 mg was partly replaced by tolvaptan of 3.75 or 7.5 mg a day as an alternative in patients with heart failure receiving furosemide more than 40 mg a day. Intervention period is 2 months. Control group: Patients with heart failure who continue to receive furosemide of more than 40 mg a day. CONDITION: chronic heart failure PRIMARY OUTCOME: The change in BNP levels from the enrolment in this trial to 2 months later. SECONDARY OUTCOME: 1) Changes in renal functional parameters: creatinine clearance, urinary microalbumin excretion, and urinary L‐FABP excretion, from the enrolment in this trial to 2 months later.; 2) Adverse events which are defined as all cause death, worsening of heart failure requiring an increase in an amount of loop diuretics, and ventricular arrhythmia which need cardioversion or defibrillation, during the period from the enrolment in this trial to 2 months later.; 3) Adverse events which are defined as cardiovascular death and/or hospitalization for heart failure during 6 months after 2 months intervention period. INCLUSION CRITERIA: Patients who are older than 20 years and have been receiving loop diuretics of the amount equivalent to more than 40 mg a day of furosemide due to chronic heart failure. The patients with in stable condition without changes in both symptoms and therapy of heart failure within one month prior to the enrolment.