Reindl M, Tiller C, Holzknecht M, et al. - Among consecutive ST-segment–elevation myocardial infarction (STEMI) patients (n = 103) managed with primary percutaneous coronary intervention, this prospective observational analysis was undertaken to explore the links between aortic stiffness and infarct healing using comprehensive cardiac magnetic resonance imaging. Within the first week post-STEMI, experts employed a verified phase-contrast cardiac magnetic resonance imaging protocol to determine pulse wave velocity (PWV), the reference standard for aortic stiffness evaluation. From baseline to 4-month follow-up, a significant reduction in median infarct size, from 17% of left ventricular mass to 12%, respectively, was noted. Relative infarct size reduction was found to be 36%. In patients who were younger and those with lower baseline N-terminal pro–B-type natriuretic peptide levels and aortic PWV values, a reduction > 36% was observed. Infarct size reduction, as evaluated by cardiac magnetic resonance, was independently predicted by aortic PWV, this revelation implies a new pathophysiological connection between aortic stiffness and adverse infarct healing during the early phase following STEMI managed with contemporary primary percutaneous coronary intervention.