title: Plasma natriuretic peptide levels increase with symptoms and severity of mitral regurgitation.
abstract: OBJECTIVE
  This paper will describe associations between plasma natriuretic peptide levels and the severity and symptoms of mitral regurgitation (MR).
  
  
  BACKGROUND
  A biochemical test that assisted grading of the severity of MR and the interpretation of symptoms would be of clinical value.
  
  
  METHODS
  Forty-nine patients with isolated MR and left ventricular (LV) ejection fractions (EFs) of >55% underwent transthoracic echocardiography, assessment of symptoms, and measurement of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and its amino-terminal portion, N-BNP.
  
  
  RESULTS
  The level of each natriuretic peptide rose with increasing severity of MR and with increases in left atrial (LA) dimensions (p < 0.001 for all comparisons), but no significant correlation existed between any natriuretic peptide and the LV dimensions or EF. Natriuretic peptide levels were higher in symptomatic MR (n = 16, BNP geometric mean 16.9 [95% confidence interval (CI) 13.3 to 21.4] pmol/l) compared with asymptomatic MR (n = 33, BNP 7.1 [95% CI 6.0 to 8.4] pmol/l, p < 0.001), and higher in asymptomatic MR than in normal controls (n = 100, BNP 5.3 [95% CI 4.8 to 5.8] pmol/l, p < 0.0001). These differences were similar for N-BNP and ANP and remained statistically significant (p < 0.05) after adjustment for echocardiographic measures of LV function and severity of MR. Both the sensitivity and the specificity for symptoms for the natriuretic peptides (area under receiver-operator characteristic curve for BNP = 0.90, N-BNP = 0.89, ANP = 0.89) were similar to the MR score (0.88) and greater than for LA dimension (0.81), vena contracta width (0.82), and LV end-systolic dimension (0.63).
  
  
  CONCLUSIONS
  Plasma natriuretic peptides levels increase with the severity of MR and are higher in symptomatic compared to asymptomatic patients, even when LV EF is normal.
authors.affiliation: Cardiology Department, Middlemore Hospital, Auckland, New Zealand.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Sutton
authors.forename: Ralph A H
authors.initials: RA
authors.lastname: Stewart
authors.forename: Ivor L
authors.initials: IL
authors.lastname: Gerber
authors.forename: Teena M
authors.initials: TM
authors.lastname: West
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Yandle
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Kerr
mesh_terms: D000328:Adult; D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood*; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000097:blood* / Q000150:complications* / Q000000981:diagnostic imaging; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009419:Nerve Tissue Proteins / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor