Significance of low-dose dobutamine stress echocardiography for the prediction of the long-term prognosis for patients with acute myocardial infarction.
OBJECTIVE
Detection of stunned myocardium using low-dose dobutamine stress echocardiography is a good predictor of improvement of cardiac function in patients with acute myocardial infarction during short hospital stays. The present study evaluated the detection of stunned myocardium as a predictor of the long-term prognosis for patients with acute myocardial infarction.


METHODS
One hundred and two patients (83 males, 19 females, mean age 61.5 years) with initial myocardial infarction underwent successful reperfusion therapy (direct percutaneous transluminal coronary angioplasty or stent) in the acute stage. Within 7 days, low-dose dobutamine was administered by intravenous drip and improvement of wall motion of the infarct area was evaluated by echocardiography. The patients were divided into two groups, the viable group that showed one grade or more improvement (61 patients), and the non-viable group that showed no improvement (41 patients). These groups were compared to determine the differences in clinical findings such as remodeling of the left ventricle measured by two-dimensional echocardiography, physical work capacity during serial multi-step exercise testing, and the prognosis.


RESULTS
The viable group showed greater improvement in hemodynamics and wall motion of the infarct areas than the non-viable group. After discharge, the physical work capacity was significantly increased and there was no recognizable enlargement of the left ventricle in the viable group. No sudden cardiac death or heart failure occurred in the viable group, in contrast to incidences of 6% and 9%, respectively, in the non-viable group. Unstable angina and nonfatal re-infarction occurred more frequently in the viable group.


CONCLUSIONS
The presence of stunned myocardium is a predictor of the prognosis for patients with acute myocardial infarction.
Kayano
Hiroyuki
H
Third Department of Internal Medicine, Showa University School of Medicine, Hatanodai 1-5-8, Shinagawa-ku, Tokyo 142-8666.
Ozawa
Masaki
M
Koh
Shuhaku
S
Sorimachi
Masami
M
Ueda
Hiroaki
H
Kawamura
Kitaro
K
Andoh
Hiromi
H
Akutsu
Yasushi
Y
Hasegawa
Masaichi
M
Katagiri
Takashi
T
D004280:Dobutamine; D004453:Echoencephalography / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology*; D011379:Prognosis; D016896:Treatment Outcome
D004280:Dobutamine