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.
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.
Bergler-Klein
Jutta
J
Department of Cardiology, Medical University of Vienna, Waehringer-Guertel 18-20, A-1090 Vienna, Austria. jutta.bergler-klein@meduniwien.ac.at
Mundigler
Gerald
G
Pibarot
Philippe
P
Burwash
Ian G
IG
Dumesnil
Jean G
JG
Blais
Claudia
C
Fuchs
Christina
C
Mohty
Dania
D
Beanlands
Rob S
RS
Hachicha
Zeineb
Z
Walter-Publig
Nicole
N
Rader
Florian
F
Baumgartner
Helmut
H
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
D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain