Sensitive detection of myocardial viability in chronic coronary artery disease by ultrasonic integrated backscatter analysis.
BACKGROUND
Myocardial viability is not synonymous with contractile reserve and identifiable in a significant percentage of dysfunctional myocardial segments without contractile reserve. The usefulness of ultrasonic tissue characterization by the phase-corrected magnitude of cyclic variation of integrated backscatter (MVIB) in chronic coronary artery disease is not fully validated. Thus, whether MVIB predominantly reflects the contractile reserve or myocardial viability of chronically dysfunctional myocardium was determined.


METHODS
The MVIB of severely dysfunctional interventricular septum or posterior wall was measured in 34 consecutive patients with previous myocardial infarction. Dobutamine stress echocardiography and fluorine-18 fluorodeoxyglucose positron emission tomography were used as the standards of contractile reserve and myocardial viability, respectively.


RESULTS
Among 44 dysfunctional segments, only 15 were judged as having contractile reserve and 29 were judged as not by dobutamine stress echocardiography, whereas 26 segments showed myocardial viability using fluorine-18 fluorodeoxyglucose positron emission tomography and 18 did not. MVIB was greater in segments with than in those without contractile reserve (4.7 +/- 2.2 vs -1.4 +/- 4.9 dB, P < .0001), but there was considerable overlap between the groups. On the other hand, MVIB of segments with and without myocardial viability (4.1 +/- 2.6 vs -4.3 +/- 3.3 dB, P < .0001) was distinctly different and predicted myocardial viability with a sensitivity of 92% and a specificity of 94%.


CONCLUSIONS
For patients with chronic coronary artery disease, MVIB better reflects myocardial viability than it does contractile reserve. Ultrasonic tissue characterization, in concordance with fluorine-18 fluorodeoxyglucose positron emission tomography, is a sensitive method for detecting myocardial viability.
Komuro
Kaoru
K
Department of Cardiovascular Medicine, Hokkaido University, Sapporo 060-8638, Japan.
Yamada
Satoshi
S
Mikami
Taisei
T
Yoshinaga
Keiichiro
K
Noriyasu
Kazuyuki
K
Goto
Kazutomo
K
Onozuka
Hisao
H
Urasawa
Kazushi
K
Fujii
Satoshi
S
Tamaki
Nagara
N
Kitabatake
Akira
A
D000368:Aged; D002908:Chronic Disease; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D025401:Echocardiography, Stress; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18