Multiparametric Cardiac Magnetic Resonance Characterization of the Noninfarcted Myocardium: Definition, Assessment, and Clinical Significance.

Acute myocardial infarction (AMI) remains a major cause of cardiovascular illness and death. Advanced imaging techniques, particularly cardiac magnetic resonance (CMR), have become essential in assessing tissue alterations within the infarcted zone. The CMR published reports focus primarily on evaluating infarct size and the peri-infarct region in the context of AMI. Recent evidence highlights that the noninfarcted myocardium (NIM) surrounding the infarct sustains functional, structural, and inflammatory changes due to ischemic injury. CMR can detect significant changes in the NIM, such as inflammation, interstitial expansion, and altered myocardial deformation. These findings indicate that the NIM is not merely passive but is actively involved in the progression of heart disease after AMI. Targeting the NIM with novel therapeutic strategies, such as antiinflammatory and antifibrotic treatments, shows promise for improving patient outcomes. This review aims to define the role and imaging criteria for exploring the NIM after AMI and to highlight its emerging significance as a tool for risk stratification and a potential therapeutic target.