title: B-type natriuretic peptide in low-flow, low-gradient aortic stenosis: relationship to hemodynamics and clinical outcome: results from the Multicenter Truly or Pseudo-Severe Aortic Stenosis (TOPAS) study.
abstract: BACKGROUND
  The prognostic value of B-type natriuretic peptide (BNP) is unknown in low-flow, low-gradient aortic stenosis (AS). We sought to evaluate the relationship between AS and rest, stress hemodynamics, and clinical outcome.
  
  
  RESULTS
  BNP was measured in 69 patients with low-flow AS (indexed effective orifice area < 0.6 cm2/m2, mean gradient < or = 40 mm Hg, left ventricular ejection fraction < or = 40%). All patients underwent dobutamine stress echocardiography and were classified as truly severe or pseudosevere AS by their projected effective orifice area at normal flow rate of 250 mL/s (effective orifice area < or = 1.0 cm2 or > 1.0 cm2). BNP was inversely related to ejection fraction at rest (Spearman correlation coefficient r(s)=-0.59, P<0.0001) and at peak stress (r(s)=-0.51, P<0.0001), effective orifice area at rest (r(s)=-0.50, P<0.0001) and at peak stress (r(s)=-0.46, P=0.0002), and mean transvalvular flow (r(s)=-0.31, P=0.01). BNP was directly related to valvular resistance (r(s)=0.42, P=0.0006) and wall motion score index (r(s)=0.36, P=0.004). BNP was higher in 29 patients with truly severe AS versus 40 with pseudosevere AS (median, 743 pg/mL [Q1, 471; Q3, 1356] versus 394 pg/mL [Q1, 191 to Q3, 906], P=0.012). BNP was a strong predictor of outcome. In the total cohort, cumulative 1-year survival of patients with BNP > or = 550 pg/mL was only 47+/-9% versus 97+/-3% with BNP < 550 (P<0.0001). In 29 patients who underwent valve replacement, postoperative 1-year survival was also markedly lower in patients with BNP > or = 550 pg/mL (53+/-13% versus 92+/-7%).
  
  
  CONCLUSIONS
  BNP is significantly higher in truly severe than pseudosevere low-gradient AS and predicts survival of the whole cohort and in patients undergoing valve replacement.
authors.affiliation: Department of Cardiology, Medical University of Vienna, Waehringer-Guertel 18-20, A-1090 Vienna, Austria. jutta.bergler-klein@meduniwien.ac.at
authors.forename: Jutta
authors.initials: J
authors.lastname: Bergler-Klein
authors.forename: Gerald
authors.initials: G
authors.lastname: Mundigler
authors.forename: Philippe
authors.initials: P
authors.lastname: Pibarot
authors.forename: Ian G
authors.initials: IG
authors.lastname: Burwash
authors.forename: Jean G
authors.initials: JG
authors.lastname: Dumesnil
authors.forename: Claudia
authors.initials: C
authors.lastname: Blais
authors.forename: Christina
authors.initials: C
authors.lastname: Fuchs
authors.forename: Dania
authors.initials: D
authors.lastname: Mohty
authors.forename: Rob S
authors.initials: RS
authors.lastname: Beanlands
authors.forename: Zeineb
authors.initials: Z
authors.lastname: Hachicha
authors.forename: Nicole
authors.initials: N
authors.lastname: Walter-Publig
authors.forename: Florian
authors.initials: F
authors.lastname: Rader
authors.forename: Helmut
authors.initials: H
authors.lastname: Baumgartner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000145:classification / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology*; D001794:Blood Pressure; D002302:Cardiac Output; D018376:Cardiovascular Abnormalities / Q000453:epidemiology; D002648:Child; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D045283:Natriuretic Agents / Q000627:therapeutic use; D020097:Natriuretic Peptide, Brain / Q000627:therapeutic use*; D016277:Ventricular Function, Left
chemical_list: D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain