Imaging in the management of ischemic cardiomyopathy: special focus on magnetic resonance

Heart failure of ischemic origin has become increasingly common over the last decade because of the improved survival of patients with acute myocardial infarction. Revascularization with coronary bypass grafting or percutaneous coronary intervention plays a pivotal role in patients with ischemic cardiomyopathy, although these interventions are often associated with relatively high peri-procedural risk. The pathophysiological substrate of ischemic cardiomyopathy is heterogeneous, varying from predominantly hibernating myocardium to irreversible scarring. There is evidence to suggest that patients with hibernating myocardium benefit most from revascularization, whereas medical therapy is associated with an adverse prognosis. Therefore, noninvasive testing is recommended by relevant guidelines to guide optimal management in these patients. However, the role of noninvasive testing has recently been challenged. There are various imaging modalities available that provide information on different aspects of the disease, and therefore, they differ significantly in sensitivity and specificity. In clinical practice, choosing among the different imaging modalities can be difficult. Cardiac magnetic resonance has evolved into a comprehensive modality that can accurately determine the amount of hibernating myocardium as well as the presence and degree of myocardial ischemia and the extent of the scar. This paper reviews the indications, accuracy, and clinical utility of the available imaging techniques, with a special focus on cardiac magnetic resonance in ischemic cardiomyopathy, and provides an outlook on how this field might evolve in the future.