Background: In successfully revascularized acute myocardial infarction (AMI), microvascular function in a myocardial flow-glucose metabolism mismatch pattern has not been reported. We aimed to elucidate myocardial flow reserve (MFR) and myocardial viability in mismatch segments.
Methods: 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and adenosine stress 13N-ammonia PET were performed in eighteen AMI patients to evaluate myocardial glucose metabolism, myocardial blood flow (MBF), and MFR. Infarct segments were classified into 3 groups: normal (preserved resting MBF), mismatch (preserved FDG uptake but reduced resting MBF), and match (reduced FDG uptake and resting MBF). Regional wall motion score (WMS) was assessed immediately after reperfusion and recovery periods.
Results: MFR in the mismatch group was significantly lower than that in non-infarct-related segments (1.655 ± 0.516 vs 2.282 ± 0.629, P < .01) and similar to that in the match group (1.635 ± 0.528, P = .999). WMS in the mismatch group was significantly improved (3.07 ± 0.48 vs 2.07 ± 1.14, P = .003); however, in recovery periods, WMS in the mismatch group was significantly higher than that in the normal group (1.05 ± 1.04, P < .01).
Conclusions: In successfully revascularized AMI, microvascular function is impaired despite preserved myocardial glucose metabolism in mismatch segments.
Keywords: 13N-ammonia PET; Flow-glucose metabolism mismatch; acute myocardial infarction; microcirculation.