title: Circulating natriuretic peptides in cats with heart disease.
abstract: BACKGROUND
  Circulating natriuretic peptide concentrations are increased in cats with myocardial dysfunction.
  
  
  OBJECTIVE
  Serum N-terminal fragment of proatrial natriuretic peptide (NT-proANP) and NT-probrain natriuretic peptide (proBNP) concentrations may predict the presence of heart disease (HD) and congestive heart failure (CHF). A positive relationship is also predicted among natriuretic peptide (NP) concentrations, a noninvasive estimate of left ventricular filling pressure (E/E(a)), and an echocardiographic measure of left atrial (LA) size (LA/aortic diameter [Ao]).
  
  
  METHODS
  Serum NP concentrations were measured in 28 healthy control and 50 study cats using sandwich enzyme immunoassays. The study group comprised cats, with HD but no CHF (HD - CHF, n = 17) and cats with CHF (HD + CHF, n = 33). The relationship among NP concentrations, LA size, and E/E(a) was examined. The ability of NP to distinguish control from study cats, and HD - CHF from HD + CHF cats, was explored using receiver operator curve analysis.
  
  
  RESULTS
  NP concentrations were significantly lower in control than in study cats (P= .0001). The NT-proBNP concentrations were positively correlated with LA/Ao ratio (rho= 0.34; P= .02) and with E/E(a) ratio (rho= 0.68; P < .05). An NT-proBNP concentration of 49 fmol/mL gave a sensitivity and specificity of 100 and 89.3%, respectively, for correctly distinguishing 96.2% of control from study cats. Pairwise comparisons of the areas under the curve identified a statistically significant difference (P= .011) between NT-proANP and NT-proBNP to distinguish control from study cats. NT-proANP and NT-proBNP concentrations were significantly higher in HD + CHF cats than in HD - CHF cats (P= .0023 and .0001, respectively).
  
  
  CONCLUSIONS
  Serum concentrations of NT-proANP and particularly NT-proBNP were different in healthy control cats, asymptomatic cats with HD, and cats with CHF, suggesting that measurement of NP concentrations may prove clinically useful as an initial screening test for cats with suspected cardiac disease.
authors.affiliation: Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hatfield, Herts, UK. dconnolly@rvc.ac.uk
authors.forename: D J
authors.initials: DJ
authors.lastname: Connolly
authors.forename: R J Soares
authors.initials: RJ
authors.lastname: Magalhaes
authors.forename: H M
authors.initials: HM
authors.lastname: Syme
authors.forename: A
authors.initials: A
authors.lastname: Boswood
authors.forename: V Luis
authors.initials: VL
authors.lastname: Fuentes
authors.forename: L
authors.initials: L
authors.lastname: Chu
authors.forename: M
authors.initials: M
authors.lastname: Metcalf
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D002371:Cat Diseases / Q000097:blood* / Q000175:diagnosis; D002415:Cats; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D008297:Male; D045265:Natriuretic Peptides / Q000097:blood*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D045265:Natriuretic Peptides