Amount of left ventricular hypertrophy determines the plasma N-terminal pro-brain natriuretic peptide level in patients with hypertrophic cardiomyopathy and normal left ventricular ejection fraction.
BACKGROUND
N-terminal pro-brain natriuretic peptide (NT-proBNP) is increased in patients with hypertrophic cardiomyopathy (HCM); however, the determinants of NT-proBNP level have not been clarified in HCM.


OBJECTIVE
This study was performed to determine the relationship between NT-proBNP levels and various echocardiographic variables of patients with HCM and normal left ventricular ejection fraction (LVEF).


METHODS
We assessed plasma NT-proBNP levels and echocardiographic variables of 36 patients (19 men, 58 +/- 14 years) with HCM and an LVEF of > or = 55%. Echocardiographic variables measured were LV wall thickness, end-diastolic LV internal dimension (LVIDd) and volume (LVEDV), LV mass, and LV mass index (LV mass/body surface area, LVMI). Left ventricular outflow tract pressure gradient, transmitral E and A velocities, deceleration time (DT) of the transmitral E wave, and septal annular E' velocity were measured by Doppler technique. The relationship between echocardiographic variables and plasma NT-proBNP level was analyzed.


RESULTS
The plasma NT-proBNP level was 775.2 +/- 994.2 pg/ml (range 33.1-4729.0 pg/ml). It showed positive correlations with LV end-diastolic septal thickness (r = 0.39, p = 0.010) and LVMI (r = 0.27, p = 0.050), while it revealed negative correlations with LVIDd (r = -0.44, p = 0.004), LVEDV (r = -0.44, p = 0.004) and DT(r = -0.31,p = 0.034). The NT-proBNP level was higher in the patients with than in those without LV diastolic dysfunction (p = 0.033) and was independently related to LVIDd (p = 0.001), LVMI (p = 0.006) and DT (p = 0.031) by multivariate analysis.


CONCLUSIONS
In patients with HCM and normal LVEF, the amount of LV hypertrophy and LV diastolic dysfunction may exert a significant role in determining plasma NT-proBNP level.
Kim
Seon Woon
SW
Department of Medicine, Cardiac and Vascular Center, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
Park
Seung Woo
SW
Lim
Seong-Hoon
SH
Kwon
Sung Uk
SU
Choi
Yu Jeong
YJ
Park
Man Ki
MK
Lee
Sang-Chol
SC
Lee
Sang Hoon
SH
Park
Jeong Euy
JE
Jeon
Eun-Seok
ES
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002312:Cardiomyopathy, Hypertrophic / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*; D013318:Stroke Volume; D016277:Ventricular Function, Left
D010446:Peptide Fragments; D011498:Protein Precursors; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain