The local inflammatory response following acute myocardial infarction (AMI) is increasingly being recognized as a central factor determining infarct healing. Myocardial inflammation can be visualized in patients using fasting 18F-FDG PET/MRI. Although this novel biosignal correlates with long-term functional outcome, the corresponding cellular substrate is not well understood. Here we present a retrospective analysis of 29 patients with AMI who underwent revascularization, suggesting a connection between post infarction myocardial fasting 18F-FDG uptake, monocyte platelet aggregates (MPA), and P2Y12 inhibition. In detail, patients with high MPA percentages of CD14highCD16+ and CD14lowCD16+ monocytes had significantly higher local 18F-FDG uptake (SUVmean) in the infarcted myocardium than patients with low MPA (p Taken together, the findings from this analysis suggest that platelet aggregability may affect monocyte extravasation into the infarcted myocardium and influence long-term functional outcome. P2Y12 inhibition may intervene in this pathophysiologic process. Prospective studies are needed to further examine this important relationship.