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

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.