Effects of Additive Tolvaptan vs. Increased Furosemide on Heart Failure With Diuretic Resistance and Renal Impairment - Results From the K-STAR Study

Abstract

Background: Although diuretic resistance leading to residual congestion is a known predictor of a poorer heart failure (HF) prognosis, better therapeutic strategies for effective and safe decongestion have not been established.

Methods and results: In this study, 81 HF patients with fluid retention (despite taking ≥40 mg/day furosemide (FUR)), with an estimated glomerular filtration rate <45 mL/min/1.73 m², were randomized into 2 groups and administered either ≤15 mg/day additive tolvaptan (TLV) or ≤40 mg/day increased FUR for 7 days. Changes in urine volume between baseline and mean urine volume during treatment were significantly higher in the TLV than FUR group (P=0.0003). Although there was no significant decrease in body weight or improved signs and symptoms of congestion between the 2 groups, the increase in serum creatinine on Day 7 from baseline was significantly smaller in the TLV than FUR group (P=0.038). Multiple logistic regression analysis revealed that additive TLV (odds ratio 0.157, 95% confidence interval 0.043-0.605, P=0.001) was an independent clinical factor for improved renal function during treatment compared with increased FUR.

Conclusions: In HF patients with residual congestion and renal dysfunction refractory to standard therapy, additive TLV increased urine volume without further renal impairment compared with patients who received an increased dose of FUR.

Keywords: Decongestion; Diuretic resistance; Tolvaptan; Worsening renal function.