title: Plasma N-terminal pro BNP and cardiotrophin-1 are elevated in aortic stenosis.
abstract: BACKGROUND
  Echocardiography with Doppler examination of the aortic valve provides a very accurate assessment of the transvalvular gradient and is used to monitor progression of aortic stenosis (AS). Plasma brain natriuretic peptide (BNP) has been shown to correlate with end-systolic wall stress in patients with AS.
  
  
  OBJECTIVE
  We hypothesized that plasma N-terminal proBNP (NT proBNP) and a newly identified cytokine cardiotrophin-1 (CT-1), which has been shown to stimulate BNP production at a transcriptional level are elevated in patients with AS and correlate to the maximum trans-valvular aortic pressure gradient (TVPG).
  
  
  METHODS
  We compared plasma NT proBNP and CT-1 in 15 AS patients [five males, mean age 79 years [range 60-94], mean TPVG 39.3 mmHg (20-100)] with 10 controls (five male, mean age 68 years [56-79]). Results are expressed as mean [ranges] and comparisons were by the Mann-Whitney test.
  
  
  RESULTS
  NT proBNP levels were elevated in AS patients [252.9 fmol/ml (79.2-541.8)] when compared with the controls (157.2 fmol/ml [104.7-236.9], P<0.005). Also CT-1 levels were elevated in AS patients (57.3 fmol/ml [33-86.3] when compared with the controls [28.3 fmol/ml (6.9-48.3), P<0.0005]. Both NT proBNP and CT-1 levels were correlated to the TVPG (r=0.53 and r=0.65, P<0.05 and P=0.009, respectively). On best subset analysis the strongest correlate with TVPG was CT-1 (R2=38%). The addition of NT proBNP did not improve diagnostic accuracy (R2=39%).
  
  
  CONCLUSIONS
  These results suggest NT proBNP and CT-1 levels increase in proportion to the TVPG and could potentially be used to monitor progression of disease non-invasively. These markers may also be useful to identify the optimum time for surgery in AS.
authors.affiliation: Department of Medicine and Therapeutics, University of Leicester, Leicester, UK.
authors.forename: S
authors.initials: S
authors.lastname: Talwar
authors.forename: P F
authors.initials: PF
authors.lastname: Downie
authors.forename: I B
authors.initials: IB
authors.lastname: Squire
authors.forename: J E
authors.initials: JE
authors.lastname: Davies
authors.forename: D B
authors.initials: DB
authors.lastname: Barnett
authors.forename: L L
authors.initials: LL
authors.lastname: Ng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000097:blood* / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D016207:Cytokines / Q000097:blood*; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D018709:Statistics, Nonparametric
chemical_list: D016207:Cytokines; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; C092073:cardiotrophin 1