Kardiologia polska 2016 12 13() doi 10.5603/KP.a2016.0168
Heart failure (HF) is a fatal disease. Plasma osmolality with individual impacts of sodium, blood urea nitrogen (BUN), and glucose has not been studied prognostically in patients with HF. This study aims to investigate the impact of serum osmolality on clinical endpoints in HF patients.
A total of 509 patients (383 males, 126 females) with heart failure with reduced ejection fraction (HFrEF) in three HF centers were retrospectively analyzed between January 2007 and December 2013. Follow up data were completed for 496 patients. Plasma osmolality was calculated as (2*Na)+(BUN/2.8)+(Glucose/18). Quartiles of plasma osmolality were produced and the possible relationship between plasma osmolality and cardiovascular mortality (CV) was investigated.
The mean follow-up was 25±22 months The mean age was 56.5±17.3 years with a mean ejection fraction (EF) of 26±8%. The mean levels of plasma osmolality were as follows in the quartiles: 1st % = 280±6, 2nd % = 288±1, 3rd % = 293±2 (95% confidence interval [CI] 292.72-293.3), 4th % = 301±5 mOsm/kg. The EF and BNP levels were similar in four quartiles. Univariate and multivariate analyses in the Cox proportional hazard model revealed a significantly higher rate of mortality in the patients with hypoosmolality. The Kaplan-Meier plot showed graded mortality curves with the 1st quartile having the worst prognosis, followed by the 4th quartile and the 2nd quartile, while the 3rd quartile was shown to have the best prognosis.
Our study results suggest that normal plasma osmolality is between 275 and 295 mOsm/kg. However, being close to the upper limit of normal range (292 to 293 mOsm/kg) seems as the optimal plasma osmolality level in terms of CV prognosis in patients with HF.