BACKGROUND: Serum osmolality has been reported to be infuenced by well-known prognostic factors such as arginine vasopressin, the renin-angiotensin-aldosterone system, and natriuretic peptides, which suggest that osmolality itself could be also associated with the prognosis of heart failure. However, previous studies in acute heart failure (AHF) reported conflicting results on the prognostic role of serum osmolality.
METHODS: We conducted a retrospective cohort study in subjects hospitalized with AHF between 2022 and 2023 in order to determine the association between serum osmolality at admission and 90-days mortality using Cox proportional hazard and Kaplen-Meier models.
RESULTS: The study group consisted of 166 AHF patients (male 51%), mean age of 80 ± 9 years) with serum osmolarity 282± 11 mOsm/L and 90-days mortality equal to 23%. At univariate analysis, osmolality was significantly associated with mortality (HR 0.96, 95% CI 0.94-0.96). The optimal cut-off values for mortality was <280 mOsm/L (AUC 0.61; VPV 33 VPN 84). After adjustment for sex, age, BNP, renal and left ventricular functions, osmolality remained significantly and independently associated with mortality (HR 0.97, 95% CI 0.95-0.99). CONCLUSIONS: Lower levels of serum osmolality on admission were related to short-term mortality in patients with AHF, suggesting that this could help stratify the risk of early mortality.