Blood Urea Nitrogen/Creatinine Ratio and Response to Tolvaptan in Patients with Decompensated Heart Failure: A Retrospective Analysis.
BACKGROUND
Arginine vasopressin-stimulated reabsorption of urea occurs in the collecting duct via increased expression of the urea transporter.


OBJECTIVE
The aim of this study was to evaluate whether the blood urea nitrogen/creatinine (BUN/Cr) ratio is useful for predicting tolvaptan response in patients with decompensated heart failure (HF).


METHODS
Among 71 consecutive patients with HF who received oral tolvaptan between 2010 and 2014, we retrospectively studied 33 patients with decompensated HF without any mechanical circulatory assistance or inotropic support who had already been treated with loop diuretics. A responder to tolvaptan was defined as an individual who experienced a ≥30 % increase in their respective 24-h urine volume.


RESULTS
Among the 33 patients, 21 met the criteria of a responder. The area under the receiver operating characteristic curves of BUN/Cr and BUN were 0.790 and 0.714, respectively, and the respective cut-off values for responders to tolvaptan were 23.8 and 49.0. BUN/Cr and BUN retained their significant relationships with the responder status (odds ratio for BUN/Cr >23.8: 20.9; 95 % confidence interval [CI] 2.7-531.1; p = 0.002; odds ratio for BUN ≥49: 7.7; 95 % CI 1.4-65.8; p = 0.02).


CONCLUSIONS
Our results suggest that high BUN/Cr may be a predictor of response to tolvaptan in decompensated HF patients. A prospective study with a large sample size is required to confirm this preliminary finding.
Department of Cardiology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
Dai
D
Okayama
Tsuyoshi
T
Suzuki
Tsuyoshi
T
Shiga
Yuichiro
Y
Minami
Shuichi
S
Tsuruoka
Nobuhisa
N
Hagiwara
D000368:Aged; D000369:Aged, 80 and over; D065092:Antidiuretic Hormone Receptor Antagonists / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology*; D001702:Biopharmaceutics / Q000379:methods; D001806:Blood Urea Nitrogen; D003404:Creatinine / Q000097:blood*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy; D006801:Humans; D008297:Male; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D000077602:Tolvaptan; D016896:Treatment Outcome
D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines; D000077602:Tolvaptan; D003404:Creatinine