Myocardial viability assessment after acute myocardial infarction: low-dose dobutamine echocardiography versus rest-redistribution thallium-201 SPECT.
BACKGROUND
The presence of tissue viability is of great importance in the prognostic work-up of patients recovering from acute myocardial infarction. However, uncertainty still exists concerning the optimal tool for its assessment. The present study was undertaken in order to compare low-dose dobutamine echocardiography and rest-redistribution thallium SPECT for predicting late improvement of regional left ventricular function after acute myocardial infarction.


METHODS
Fifteen patients undergoing coronary angiography, low-dose dobutamine echocardiography and rest-redistribution thallium SPECT after thrombolyzed anterior acute myocardial infarction were studied. A 3 month follow-up echocardiogram was performed in all patients and 9 underwent coronary revascularization.


RESULTS
A significant (> or = 70%) residual stenosis of the infarct-related artery was present in 14 patients, whilst a total occlusion was observed in 1. At 3 month follow-up, 41% of the dyssynergic segments improved. The sensitivity, specificity and accuracy for late wall motion improvement was 61, 89 and 77% for low-dose dobutamine echocardiography and, respectively, 76, 45 and 58% for rest-redistribution thallium SPECT. Tissue viability was detected in 65 and 31% of dyssynergic segments by rest-redistribution thallium SPECT and low-dose dobutamine echocardiography, respectively (p < 0.001). The agreement between the two techniques was 48%.


CONCLUSIONS
Low-dose dobutamine echocardiography is more accurate than rest-redistribution thallium SPECT for predicting 3 month wall motion improvement in patients with acute anterior myocardial infarction, mainly due to its significantly better specificity.
Castini
D
D
Divisione di Cardiologia, Università degli Studi, Ospedale San Paolo, Milano. castini@ats.it
Bestetti
A
A
Garbin
M
M
Di Leo
C
C
Bigi
R
R
Sponzilli
C
C
Concardi
G
G
Gioventù
M
M
Tarolo
G L
GL
Lombardi
F
F
Fiorentini
C
C
D000328:Adult; D002316:Cardiotonic Agents / Q000008:administration & dosage; D017023:Coronary Angiography; D004280:Dobutamine / Q000008:administration & dosage; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011379:Prognosis; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes / Q000008:administration & dosage; D014022:Tissue Survival; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D002316:Cardiotonic Agents; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D004280:Dobutamine