Use of tolvaptan in patients hospitalized for worsening chronic heart failure with severe hyponatremia: The initial experience at a single-center in Turkey.

Objective: The aim of the present study was to assess the efficacy and safety of tolvaptan for severe hyponatremia (SH) in hypervolemic heart failure (HF) patients within daily clinical practice.

Methods: We restrospectively reviewed our database on tolvaptan as an add-on treatment in hypervolemic patients admitted to our clinic due to deterioration of HF and having hyponatremia resistant to standard therapy. Severe hyponatremia was defined as serum sodium concentration ≤125 mEq/L. The database included demographic, clinical, laboratory, and echocardiographic findings on admission, and numerous outcome measures for oral tolvaptan treatment were used to assess its efficacy and safety.

Results: The study group consisted of 56 hypervolemic HF patients with severe hyponatremia (25 female and 31 male) with mean age of 66 years. All patients received a single dose of tolvaptan 15 mg daily for an average of 3.2 days due to severe hyponatremia. Sodium and potassium concentrations, fluid intake, and urine volume increased (p<0.0001, p=0.037, p<0.0001, and p<0.0001, respectively), whereas furosemide dosage, body weight, heart rate, systolic and diastolic blood pressure, and New York Heart Association class decreased significantly in response to tolvaptan treatment, without a rise in serum creatinine or urea concentrations (p<0.0001, p<0.0001, p=0.001, p<0.049, p<0.009 ve p=0.001, respectively).

Conclusion: In this retrospective, single-centered study conducted in a small group of Turkish patients, short-term treatment with low-dose tolvaptan added to standard therapy of hypervolemic HF patients with severe hyponatremia was well tolerated with a low rate of major side effects and was effective in correcting severe hyponatremia.