Young Mice Exhibit Increased Relative Ventricular Remodeling After AMI —A Longitudinal CMR Study

ABSTRACT Cardiovascular diseases are the leading cause of mortality worldwide, with myocardial infarction (MI) contributing significantly to this burden. While age‐related differences in cardiac remodeling and healing post MI are well‐documented clinically, appropriate pre‐clinical studies are needed to evaluate the underlying pathological mechanisms and to further improve therapeutic interventions. Here, we compared LV remodeling between young and aged C57BL/6 mice, following permanent LAD ligation, using CMR imaging after 2, 7, and 28 days of MI induction. At baseline conditions, aged mice exhibited higher end‐diastolic and end‐systolic volumes and tended to have a reduced deformation capacity. Post‐MI, both groups showed significant LV dilation, loss of contractility, and impaired ejection fraction. Interestingly, young mice undergo larger proportional geometric changes relative to their pre‐infarction state. At the same time, histological data of labeled heart sections pointed to a more rapid healing process in young animals. These findings highlight the critical role of age in modulating cardiac remodeling and, thus, challenge the commonly held hypothesis of an age‐dependent increase of LV remodeling.