Prediction of recovery of left ventricular dysfunction after acute myocardial infarction: comparison between 99mTc-sestamibi cardiac tomography and low-dose dobutamine echocardiography.
The aim of this study was to evaluate the role of 99mTc-sestamibi cardiac imaging and dobutamine echocardiography in detecting myocardial viability early after acute myocardial infarction.


METHODS
Forty-nine patients (mean age 52 +/- 10 y) underwent coronary angiography, low-dose dobutamine echocardiography, radionuclide angiography and rest 99mTc-sestamibi imaging within 10 d after myocardial infarction. Of these patients, 19 were revascularized and 30 were treated medically. Resting echocardiogram and radionuclide angiography were repeated 8 mo later to evaluate segmental functional recovery and changes in left ventricular (LV) ejection fraction, respectively.


RESULTS
In revascularized patients, 61 of 108 akinetic or dyskinetic segments showed functional recovery. In these patients, sensitivity in predicting segmental functional recovery was 87% for sestamibi imaging and 66% for dobutamine echocardiography (P < 0.001), whereas specificity and accuracy were comparable. Sestamibi activity (> or =55% of peak) was the strongest predictor of segmental functional recovery (P < 0.001) and of LV ejection fraction improvement > or =5% (P < 0.01) after revascularization. In medically treated patients, 60 of 149 akinetic or dyskinetic segments showed functional recovery. In these patients, the majority (94%) of segments with contractile reserve on dobutamine were viable on sestamibi imaging and 86% of them improved function at follow-up. Functional recovery was poor in segments without contractile reserve either with (38%) or without (62%) preserved sestamibi uptake. Inotropic response was the best predictor of segmental (P < 0.001) and global (P < 0.01) LV functional improvement in medically treated patients.


CONCLUSIONS
Dobutamine echocardiography predicts spontaneous functional recovery after acute myocardial infarction. However, sestamibi imaging is useful to identify patients with dysfunctional myocardium without contractile reserve who may benefit from coronary revascularization.
Spinelli
L
L
Institute of Internal Medicine, Cardiology and Heart Surgery, Nuclear Medicine Center of the National Council of Research, Naples, Italy.
Petretta
M
M
Cuocolo
A
A
Nicolai
E
E
Acampa
W
W
Vicario
L
L
Bonaduce
D
D
D000208:Acute Disease; D017130:Angioplasty; D002316:Cardiotonic Agents; D004280:Dobutamine; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D009204:Myocardial Revascularization; D011379:Prognosis; D012372:ROC Curve; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left
D002316:Cardiotonic Agents; D019275:Radiopharmaceuticals; D004280:Dobutamine; D017256:Technetium Tc 99m Sestamibi