A novel global strain diastolic index correlates with plasma NT-proBNP levels in asymptomatic hypertensive patients with preserved left ventricular ejection fraction.
BACKGROUND
The strain imaging diastolic index (SI-DI) was reported to be a sensitive marker of regional left ventricular (LV) delayed relaxation induced by ischemia. However, the clinical usefulness of the global SI-DI has not been evaluated. N-terminal pro-brain natriuretic peptide (NT-proBNP) is a sensitive biomarker for the detection of asymptomatic diastolic LV dysfunction. This study investigated the ability of a novel parameter, the global SI-DI, obtained using 2D speckle tracking imaging (2DSI) to correlate with the plasma NT-proBNP levels in asymptomatic hypertensive patients with preserved LV ejection fraction.


METHODS
We performed 2D echocardiography and 2DSI in 83 asymptomatic hypertensive patients with preserved ejection fraction (>45 %) and in 37 control subjects. In 2DSI, the LV longitudinal peak strain and the SI-DI of 18 LV segments were measured. NT-proBNP was measured in all subjects. The data were compared between hypertensive patients and normal controls.


RESULTS
The average peak strain and global SI-DI of 18 LV segments were significantly reduced in hypertensive patients compared with control subjects (P < 0.05); however, only the global SI-DI was significantly correlated with log10 NT-proBNP (r = -0.469, P = 0.001). In Pearson's correlation analyses, log10 NT-proBNP was significantly correlated with E/e', E/A ratio, early diastolic mitral annular velocity (e'), global peak strain, deceleration time of the E-wave, and LV ejection fraction. In the multiple stepwise regression analysis, the global SI-DI was the strongest independent determinant of log10 NT-proBNP (β = -0.386, P = 0.008).


CONCLUSIONS
The global SI-DI derived from 2DSI correlates well with plasma NT-proBNP levels and may have prognostic value in asymptomatic hypertensive patients with preserved ejection fraction.
Division of Cardiology, Department of Internal Medicine and Pediatrics, Taipei City Hospital Zhongxiao Branch, National Yang-Ming University, Taipei, Taiwan.|Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Shuo-Ju
SJ
Chiang
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan. mdaimon@juntendo.ac.jp.
Masao
M
Daimon
Department of Cardiology, Kansai Electric Power Hospital, Osaka, Japan.
Katsuhisa
K
Ishii
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Sakiko
S
Miyazaki
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Yoko
Y
Koiso
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Hiromasa
H
Suzuki
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Katsumi
K
Miyauchi
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Bei
B
Yang
Division of Cardiology, Department of Internal Medicine and Pediatrics, Taipei City Hospital Zhongxiao Branch, National Yang-Ming University, Taipei, Taiwan.
Mei-Hsiu
MH
Yeh
Division of Cardiology, Department of Internal Medicine and Pediatrics, Taipei City Hospital Zhongxiao Branch, National Yang-Ming University, Taipei, Taiwan.
Betau
B
Hwang
Department of Cardiology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo, 113-8421, Japan.
Hiroyuki
H
Daida
Brain natriuretic peptides; Echocardiography; Hypertension; Ultrasonic diagnosis