Serum Potassium and Creatinine Levels Determine Responsiveness of Tolvaptan in Patients with Heart Failure

Objective: We investigated the effectiveness and predictors of response of tolvaptan in hospitalized patients with heart failure in a multi-center study. Method: We enrolled hospitalized patients with heart failure with excess fluid retention despite receiving oral diuretics. Clinical parameters were obtained from in hospitalized patients with heart failure, who received 3.75 to 15 mg of daily dose of tolvaptan. Results: Tolvaptan was administered to 66 patients (48 males, mean age was 70.3, NYHA class 2:3:4 was 7:42:15). During hospitalization, urinary volume increased (pre 1252 ml, post 1843 ml, P = .0001) and body weight decreased significantly (pre 64.1 kg, post 59.8 kg, P = .0001), without significant changes in blood pressure, heart rate, creatinine level, and adverse effects. The day obtained maximum daily urine volume was distributed from day 1 to day 14 after tolvaptan administration. We divided participants into two groups by the day obtained maximum daily urine volume within 2 days or not (early responder 22, non-early responders 44). Multivariable logistic regression analysis confirmed that serum potassium levels and serum creatinine levels were the independent predictors of early responders to tolvaptan (serum potassium levels: OR 0.20, 95% CI 0.05–0.78, P = .021, serum creatinine levels: OR 2.69, 95% CI 1.08–6.71, P = .033). Conclusions: Serum potassium and creatinine levels may be important predictors for the chronological responsiveness to tolvaptan in patients with heart failure.