Early assessment of regional myocardial blood flow and  metabolism in thrombolysis in myocardial infarction flow grade 3 reperfused myocardial infarction using carbon-11-acetate.
OBJECTIVE
The aim of this study was to investigate the prognostic value of carbon-11-acetate (acetate) positron emission tomography (PET) after successful reperfusion of myocardial infarction (MI).


BACKGROUND
Acetate PET allows the measurement of both myocardial flow and oxidative metabolism. The prognostic value of acetate measurements performed early (within 24 h) after Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 reperfused MI is unknown.


METHODS
In 18 patients with TIMI flow grade 3 reperfusion of their first MI, a dynamic acetate study was performed within 24 h of the acute event. At five days, nitrogen-13-NH3 (NH3) and fluorine-18-labeled fluorodeoxyglucose (FDG) PET studies were performed. Infarct-related areas were classified as "PET viable" or "PET nonviable," as assessed with NH3 and FDG, according to previously established criteria. At five days and three months, radionuclide angiography was performed for evaluation of left ventricular (LV) function.


RESULTS
In infarct-related regions, myocardial blood flow, FDG uptake and oxygen consumption were decreased, compared with remote regions. However, oxygen consumption values, as measured with acetate in both PET-viable and PET-nonviable areas, as assessed with NH3 and FDG, were not significantly different (p = NS). A significant linear correlation was observed between global LV ejection fraction at three months and oxidative metabolism in the infarct-related area (r = 0.8, p < 0.0001). Multivariate analysis revealed that oxidative metabolism measurements in reperfused myocardium was the only significant predictor for recovery of LV function at three months (p < 0.05).


CONCLUSIONS
Measurement of oxidative metabolism early after TIMI flow grade 3 reperfusion of MI offers important prognostic value concerning LV function at follow-up.
Maes
A F
AF
Department of Nuclear Medicine, UZ Gasthuisberg, Leuven, Belgium.
Van de Werf
F
F
Mesotten
L V
LV
Flamen
P B
PB
Kuzo
R S
RS
Nuyts
J L
JL
Mortelmans
L
L
D000085:Acetates; D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes; D003326:Coronary Circulation / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy*; D015428:Myocardial Reperfusion Injury / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011875:Radionuclide Angiography; D015912:Thrombolytic Therapy; D014055:Tomography, Emission-Computed
D000085:Acetates; D002250:Carbon Radioisotopes