Prognostic Impact of Early Changes in Serum Chloride Concentrations Among Hospitalized Acute Heart Failure Patients　― A Retrospective Cohort Study ―

Background: Serum electrolyte concentrations on admission and after the administration of loop diuretics may be associated with prognosis in patients hospitalized due to acute heart failure (AHF). This study investigated the prognostic impact of early changes in chloride (Cl) concentrations after diuretic administration, according to stratified Cl concentrations on admission, in AHF. Methods and Results: In all, 355 consecutive patients hospitalized due to AHF were included in this single-center retrospective cohort study. Patients were divided into 2 groups based on whether Cl decreased (n=196) or not (n=159) during the first 5 days in hospital. These 2 groups were further stratified according to Cl on admission into 4 groups: Group 1, decrease in Cl and no hypochloremia (n=127); Group 2, decrease in Cl and hypochloremia (n=69); Group 3, no decrease in Cl and no hypochloremia (n=50); and Group 4, no decrease in Cl and hypochloremia (n=109). The risk of death was significantly higher in the group without than with a decrease in Cl (all-cause death hazard ratio [HR] 1.79; 95% confidence interval [CI] 1.15–2.78; P=0.009). Group 4 had the worst prognosis and a significantly higher risk of death (all-cause death [vs. Group 1 as a reference], HR 2.51; 95% CI 1.45–4.32; P=0.001). Conclusions: The absence of an early decline in Cl was associated with poor prognosis in AHF, especially in patients with hypochloremia on admission.