Cardiac Imaging in Acute Coronary Syndromes and Acute Myocardial Infarction – An Update

Myocardial perfusion imaging (MPI) using nuclear techniques is a well-established diagnostic tool in the management of patients after acute coronary syndromes (ACS) or acute myocardial infarction (AMI) providing non-invasively information about perfusion and function. Single photon emission computed tomography (SPECT) is routinely applied for MPI allowing the characterization of localization, extent and severity of perfusion abnormalities. Gated SPECT MPI is a technique that can accurately define the individual patient risk among clinically stable survivors of AMI, assessing the total left ventricular (LV) perfusion defect size, the extent of inducible ischaemia and the degree of LV dysfunction. The documented prognostic value of these scintigraphic parameters is of clinical importance to guide decision making in the cardiac patient. Moreover, the cost effectiveness of implemented MPI in the work-up of patients after AMI has been demonstrated. Metabolic imaging with F-18 deoxyglucose positron emission tomography (PET) is currently the most advanced scintigraphic imaging technique developed for in vivo assessment of tissue viability, providing clinical valuable information about the presence and extent of viable myocardium in patients with coronary artery disease. Whether this technique will be valuable for patients with ACS or AMI has not been established, yet. However, PET technology offers fascinating opportunities to investigate the distinct pathophysiological pathways in acute and chronic cardiac disease. Imaging of stunning in Takotsubo cardiomyopathy is an example of how nuclear medicine techniques contribute to the understanding of cardiac disease.