A reverse flow-metabolism mismatch pattern on PET is related to multivessel disease in patients with acute myocardial infarction

Abstract

Hypoperfused myocardium with increased uptake of 18F-fluorodeoxyglucose (FDG) is considered to be ischemic but viable myocardium. However, the significance of a more severe defect of FDG than of 13N ammonia (NH3) (i.e., reverse flow-metabolism mismatch) is not well understood.

Methods: To study a reverse flow-metabolism mismatch pattern, PET with NH3 and FDG under glucose loading was performed in 35 patients within 2 wk after onset of first acute myocardial infarction (AMI) and in 29 patients with old myocardial infarction (OMI). The left ventricle was divided into nine segments on a bull's eye polar map, and the mean counts of NH3 (%NH3) and FDG (%FDG) were compared for the segment with the least %NH3.

Results: Ten patients in the AMI group demonstrated a marked reverse flow-metabolism mismatch pattern (greater than 10% difference between %NH3 and %FDG), whereas only 2 patients in the OMI group demonstrated the mismatch pattern (P < 0.05). Sixteen patients with AMI demonstrated %FDG > %NH3 (group 1), and 19 patients with AMI demonstrated %FDG < %NH3 (group 2). There were no significant differences in age, sex, location of infarction, diameter of stenosis of infarct-related artery or left ventricular ejection fraction between groups 1 and 2. Eleven patients in group 2 and only 3 in group 1 had multivessel disease (P < 0.02). There was no significant relationship between the number of diseased vessels and the flow-metabolism pattern in patients with OMI.

Conclusion: The finding of a reverse flow-metabolism mismatch on PET in the subacute phase of myocardial infarction was closely related to multivessel disease.