Metabolic tissue characterization in patients with acute myocardial infarction with positron tomography

Identification of myocardium at risk in acute myocardial infarction (AMI) is important for patient management. The authors previously demonstrated in animals that reversible tissue injury can be identified with PET and tracers of metabolism. To characterize reginal metabolism in AMI, 12 patients were studied <72 hours after onset of symptoms with positron tomography (PET). Regional wall motion (WM) was assessed by 2D echocardiography at the time of the PET study and again 6 weeks later. Myocardial blood flow (MBF) and exogenous glucose utilization were measured with N-13 ammonia and F-18 deoxyglucose in 5 LV segments in each patient and compared to regional WM. MBF was decreased in 29 LV segments. The irreversible tissue injury can be identified early in patients with AMI. PET frequently reveals persistent glucose utilization in ''infarcted'' myocardium when studied within 72 hours after AMI. Persistent exogenous glucose utilization detected by PET early after AMI can identify viable but jeopardized myocardium and may predict subsequent functional recovery