Abstract 6994: Impact of Urine Osmolality at Discharge on Prognosis in Heart Failure Patients

Introduction: Urine osmolality (U-OSM) is determined by the balance of water and solutes, antidiuretic hormone, and renal function. U-OSM can be altered in heart failure (HF) patients, and is influenced by multiple factors, including volume status, diuretics, and so on. However, it is not known whether U-OSM is a predictive factor of prognosis among symptomatic HF patients. Hypothesis: The aim of the study is to clarify the impact of U-OSM at discharge according to baseline renal dysfunction on prognosis among symptomatic HF patients. Methods: This study is a sub-analysis from HIJ-HF-III, which is a single center registry that collected prospectively consecutive 1,408 HF patients hospitalized at Tokyo Women’s Medical University from 2015 to 2019. 745 HF patients who were discharged alive and had available data of U-OSM at discharge were included in this study. The primary endpoint is all cause death after discharge. Results: Mean age was 69 +/- 14.8 years old, 60.1 % of the patients were male. 36.3 % of the patients had renal dysfunction. Median U-OSM at discharge was 465 mOsm/l. During the median follow-up period of 20.1 months after discharge, 108 (14.5 %) patients were died. Kaplan-Meier survival analysis showed that low U-OSM at discharge was associated with high mortality among HF patients with renal dysfunction (p=0.049). On the other hand, there was not associated between U-OSM and mortality after discharge among HF patients without renal dysfunction (p=0.944). Multivariate logistic regression showed that low U-OSM at discharge was independently associated with increased the risk of death (hazard ratio [per 1 mOSM/l]: 1003, 95%CI 1.000-1.005, p=0.041) among HF patients with renal dysfunction. Conclusion: Among HF patients with renal dysfunction, low U-OSM at discharge was significantly associated with poor outcome after discharge.