title: Hyponatraemia predicts the acute (type 1) cardio-renal syndrome.
abstract: OBJECTIVE
  The acute (type 1) cardio-renal syndrome (CRS) refers to an acute worsening of heart function leading to worsening renal function (WRF), and frequently complicates acute decompensated heart failure (ADHF) and acute myocardial infarction (AMI). The aim of this study was to investigate whether hyponatraemia, a surrogate marker of congestion and haemodilution and of neurohormonal activation, could identify patients at risk for WRF.
  
  
  RESULTS
  We studied the association between hyponatraemia (sodium <136 mmol/L) and WRF (defined as an increase of >0.3 mg/dL in creatinine above baseline) in two separate cohorts: patients with ADHF (n = 525) and patients with AMI (n = 2576). Hyponatraemia on admission was present in 156 patients (19.7%) with ADHF and 461 patients (17.7%) with AMI. Hyponatraemia was more frequent in patients who subsequently developed WRF as compared with patients who did not, in both the ADHF (34.6% vs. 22.2%, P = 0.0003) and AMI (29.7% vs. 21.8%, P<0.01) cohorts. In a multivariable logistic regression model, the multivariable adjusted odds ratio for WRF was 1.90 [95% confidence interval (CI) 1.25-2.88; P = 0.003] and 1.56 (95% CI 1.13-2.16; P = 0.002) in the ADHF and AMI cohorts, respectively. The mortality risk associated with hyponatraemia was attenuated in the absence of WRF.
  
  
  CONCLUSIONS
  Hyponatraemia predicts the development of WRF in two clinical scenarios that frequently lead to the type I CRS. These data are consistent with the concept that congestion and neurohormonal activation play a pivotal role in the pathophysiology of acute cardio-renal failure.
authors.affiliation: Department of Cardiology, Rambam Medical Center, Haifa, Israel.
authors.forename: Doron
authors.initials: D
authors.lastname: Aronson
authors.forename: Wisam
authors.initials: W
authors.lastname: Darawsha
authors.forename: Marina
authors.initials: M
authors.lastname: Promyslovsky
authors.forename: Marielle
authors.initials: M
authors.lastname: Kaplan
authors.forename: Zaid
authors.initials: Z
authors.lastname: Abassi
authors.forename: Badira F
authors.initials: BF
authors.lastname: Makhoul
authors.forename: Alexander
authors.initials: A
authors.lastname: Goldberg
authors.forename: Zaher S
authors.initials: ZS
authors.lastname: Azzam
mesh_terms: D000208:Acute Disease; D000368:Aged; D015415:Biomarkers / Q000097:blood; D059347:Cardio-Renal Syndrome / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D015994:Incidence; D007557:Israel / Q000453:epidemiology; D007902:Length of Stay / Q000639:trends; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D012964:Sodium / Q000097:blood*
chemical_list: D015415:Biomarkers; D012964:Sodium
keywords: Acute heart failure; Acute myocardial infarction; Cardio-renal syndromes; Worsening renal function