title: Hypochloraemia as a predictor of developing hyponatraemia and poor outcome in acute heart failure patients.
abstract: OBJECTIVE
  Heart failure (HF) is a major public health issue currently affecting more than 23 million patients worldwide. Hyponatraemia has been shown to be a predictor of poor outcome in patients with acute and chronic HF. Therefore, we aimed at finding a marker for early detection of patients at risk for developing hyponatraemia. To this end, the present study investigated the relationship between initial serum chloride and follow-up sodium levels in acute heart failure (AHF) patients.
  
  
  RESULTS
  The present study was performed as a prospective, single-centre, observational research with a total of 152 hospitalised AHF patients. Compared to patients with initial normochloraemia, patients with initial hypochloraemia had a statistically significantly higher incidence of hyponatraemia after a 3-month follow-up [P<0.001; odds ratio (OR)=27.08, CI: 4.3-170.7]. A similar finding was obtained upon exclusion of patients with initial hyponatraemia with Fishers test [P=0.034; odds ratio (OR)=15.5, CI:1.7-140.6]. Binary logistic regression revealed a significantly increased in-hospital mortality in the hypochloraemic/normonatriaemic (OR=4.08, CI 1.08-15.43, P=0.039), but not in the hypochloraemic/hyponatraemic, normochloraemic/hyponatraemic or normonatriaemic/normochloraemic patients. Ejection fraction (EF) at admission was significantly higher in hypochloraemic/normonatriaemic, compared to normonatriaemic/normochloraemic patients, but similar to EF in both hypochloraemic/hyponatraemic and normochloraemic/hyponatraemic patients. The N-terminal precursor Brain Natriuretic Peptide (Nt-proBNP) levels at admission were significantly lower in hypochloraemic/normonatriaemic compared to hypochloraemic/hyponatraemic and normonatriaemic/normochloraemic patients, respectively.
  
  
  CONCLUSIONS
  The data show that initial low serum chloride concentration is predictive of developing hyponatraemia and associated with increased in-hospital mortality in AHF patients.
authors.affiliation: University Hospital Centre Zagreb, Zagreb, Croatia. Electronic address: bojanara84@yahoo.com.
authors.forename: Bojana
authors.initials: B
authors.lastname: Radulović
authors.affiliation: University Hospital Centre Sisters of Charity, Zagreb, Croatia.
authors.forename: Ines
authors.initials: I
authors.lastname: Potočnjak
authors.affiliation: University Hospital Centre Sisters of Charity, Zagreb, Croatia.
authors.forename: Sanda
authors.initials: S
authors.lastname: Dokoza Terešak
authors.affiliation: University Hospital Centre Sisters of Charity, Zagreb, Croatia; University of Zagreb School of Medicine, Zagreb, Croatia.
authors.forename: Matias
authors.initials: M
authors.lastname: Trbušić
authors.affiliation: University Hospital Centre Sisters of Charity, Zagreb, Croatia; University of Zagreb Faculty of Pharmacy and Biochemistry, Zagreb, Croatia.
authors.forename: Nada
authors.initials: N
authors.lastname: Vrkić
authors.affiliation: University Hospital Centre Sisters of Charity, Zagreb, Croatia.
authors.forename: Davorin
authors.initials: D
authors.lastname: Malogorski
authors.affiliation: Clinical Hospital "Sv.Duh", Zagreb, Croatia.
authors.forename: Neven
authors.initials: N
authors.lastname: Starčević
authors.affiliation: Andrija Štampar School of Public Health, University of Zagreb School of Medicine, Zagreb, Croatia.
authors.forename: Milan
authors.initials: M
authors.lastname: Milošević
authors.affiliation: Institute of Molecular Biology and Biochemistry, Centre of Molecular Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Saša
authors.initials: S
authors.lastname: Frank
authors.affiliation: University Hospital Centre Sisters of Charity, Zagreb, Croatia; University of Zagreb School of Medicine, Zagreb, Croatia. Electronic address: vesna.degoricija@mef.hr.
authors.forename: Vesna
authors.initials: V
authors.lastname: Degoricija
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002712:Chlorides / Q000097:blood*; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000401:mortality; D006801:Humans; D007010:Hyponatremia / Q000097:blood* / Q000175:diagnosis; D016015:Logistic Models; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies
chemical_list: D002712:Chlorides
keywords: Acute heart failure; Hypochloraemia; Hyponatraemia; Survival