title: Calcium, phosphate and calcium phosphate product are markers of outcome in patients with chronic heart failure.
abstract: BACKGROUND
  Serum calcium (Ca) and inorganic phosphate (Pi) concentrations and calcium-phosphate product (CPP) levels are positively associated with worse outcomes in patients with chronic kidney disease, but there are few data for Pi or Ca and none for CPP in patients with chronic heart failure (CHF).
  
  
  METHODS
  Unselected, consecutive patients with CHF (left ventricular ejection fraction, LVEF ≤45%) were enrolled in a prospective observational study for the occurrence of hospitalisation and mortality. Blood samples were collected at the time of recruitment and analysed immediately.
  
  
  RESULTS
  Patients (n = 713) were on contemporary optimal treatment and mean (standard error, SE) follow-up was 765 (18.9) days. Mean (SE) Ca was 2.29 (0.004) mmol/l. Median (interquartile range, IQR) Pi was 1.11 (0.98-1.23) mmol/l and median CPP 2.53 (2.21-2.88) mmol(2)/l(2). LVEF correlated inversely with Ca, natural log-transformed (Ln)Pi, and LnCPP. There was no difference in CPP between classes of symptom severity or diabetes status. Ca and LnCPP (but not LnPi) were associated with total mortality. Ca was significantly associated with progressive HF and non-cardiovascular death but not with sudden death. Binary logistic regression analyses showed that LnPi and LnCPP were associated with risk of hospitalisation.
  
  
  CONCLUSIONS
  Ca, Pi and CPP could be useful additional variables in determining risk in CHF patients. Further work is required to elucidate the mechanisms underlying the adverse influence and determine whether lowering phosphate levels per se in CHF patients is of benefit.
authors.affiliation: Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics, Multidisciplinary Cardiovascular Research Centre, University of Leeds, Clarendon Way, Leeds, LS2 9JT, UK.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Cubbon
authors.forename: Ceri Haf
authors.initials: CH
authors.lastname: Thomas
authors.forename: Michael
authors.initials: M
authors.lastname: Drozd
authors.forename: John
authors.initials: J
authors.lastname: Gierula
authors.forename: Haqeel A
authors.initials: HA
authors.lastname: Jamil
authors.forename: Rowenna
authors.initials: R
authors.lastname: Byrom
authors.forename: Julian H
authors.initials: JH
authors.lastname: Barth
authors.forename: Mark T
authors.initials: MT
authors.lastname: Kearney
authors.forename: Klaus K A
authors.initials: KK
authors.lastname: Witte
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood*; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000209:etiology / Q000401:mortality*; D006760:Hospitalization; D006801:Humans; D008297:Male; D010710:Phosphates / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000097:blood* / Q000150:complications / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D010710:Phosphates; D002118:Calcium