Abstract 11007: Biochemical Urinalysis Predicts the Type of Decongestion and Worsening Renal Function due to Tolvaptan Administration in Patients With Acute Decompensated Heart Failure

Abstract

Introduction: The diuretic response to tolvaptan (TLV) varies among patients with acute decompensated heart failure (ADHF). Although TLV is known to induce the excretion of free water, the accelerated excretion of sodium and urea has also been observed to varying degrees. Purpose: To classify the types of decongestion induced by TLV based on the initial induction of urinary sodium and urea excretion. Methods: We analyzed 90 ADHF patients who had been administered TLV. As markers of the initial TLV-induced excretion of sodium and urea, we measured changes in the fractional excretion of sodium (ΔFENa) and urea (ΔFEUN) prior to the first TLV administration and after eight hours. To evaluate the clinical course until normalization, 3-day and 7-day changes in body weight (ΔBW3, ΔBW7) and the inverse of hematocrit (Δ1/Ht3, Δ1/Ht7) after TLV administration were analyzed as markers of whole body and intravascular dehydration, respectively. Worsening renal function was assessed using 7-day changes in serum urea nitrogen (ΔUN7) and creatinine (ΔCr7) concentration. Results: Our analysis revealed negative correlations between ΔFEUN and ΔBW3 (r=-0.65, p<0.001) and between ΔFENa and Δ1/Ht3 (r=-0.53, p<0.001). Based on these findings, subjects were categorized into three groups. Firstly, subjects with positive and negative ΔFEUN were designated responders (n=60) and non-responders (n=30), respectively. Responders were further categorized based on the median value of ΔFENa (0.7%), where ΔFENa≥0.7 was the Natriuresis Group (n=30) and ΔFENa<0.7 was the Aquaresis Group (n=30). During the 7 days after TLV administration, whole body dehydration was lowest in non-responders, intravascular dehydration was highest in the Natriuresis Group, and worsening renal function was lowest in the Aquaresis Group (Table). Conclusions: The initial induction of urinary sodium and urea excretion by TLV was able to predict the type of decongestion and worsening renal function in ADHF patients.