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.