Determinants and clinical significance of natriuretic peptides and hypertrophic cardiomyopathy.
OBJECTIVE
Atrial and brain natriuretic peptide levels closely reflect impaired left ventricular function in patients with heart failure. In the present study we assessed the determinants and the clinical significance of atrial and brain natriuretic peptide plasma levels in hypertrophic cardiomyopathy.


RESULTS
In 44 patients with hypertrophic cardiomyopathy (40+/-15 years) we evaluated: (a) atrial and brain natriuretic peptide plasma levels; (b) left ventricular hypertrophy; (c) left ventricular ejection fraction; (d) transmitral and pulmonary venous flow velocity patterns, and left atrial fractional shortening; (e) left ventricular outflow tract gradient; (f) maximal oxygen consumption. Left ventricular hypertrophy influenced only brain natriuretic peptide levels (r=0.32;P<0.05). Atrial and brain natriuretic peptide plasma levels did not correlate with left ventricular ejection fraction, but correlated with left ventricular outflow tract gradient (r=0.35;P<0.05; and r=0.40, P=0.022, respectively) and left atrial fractional shortening (r=-0.57;P<0.001, and r=-0.35;P<0.05, respectively). Atrial but not brain natriuretic peptide plasma levels were inversely related to maximal oxygen consumption (r=-0.35;P<0.05). By stepwise multiple regression analysis, left atrial fractional shortening and left ventricular outflow tract gradient were the only predictors of atrial and brain natriuretic peptide plasma levels, respectively.


CONCLUSIONS
In hypertrophic cardiomyopathy, atrial natriuretic peptide plasma levels are mainly determined by diastolic function: this explains the relationship with exercise tolerance. In contrast, brain natriuretic peptide plasma levels are mainly determined by left ventricular outflow tract gradient.
Briguori
C
C
Department of Cardiology and Cardiac Surgery, 'Federico II' University School of Medicine, Naples, Italy.
Betocchi
S
S
Manganelli
F
F
Gigante
B
B
Losi
M A
MA
Ciampi
Q
Q
Gottilla
R
R
Violante
A
A
Tocchetti
C G
CG
Volpe
M
M
Chiariello
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood*; D002312:Cardiomyopathy, Hypertrophic / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D012044:Regression Analysis; D013318:Stroke Volume; D016277:Ventricular Function, Left
D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor