Abstract
Acute myocardial infarction (MI) is a major cardiovascular event and a leading cause of mortality worldwide. Beyond the initial ischemic injury, the inflammatory and immune responses play pivotal roles in both tissue damage and subsequent healing. While the anti-inflammatory strategies targeting neutrophil-driven injury have demonstrated potential in limiting early cardiac damage, growing evidence highlights the critical role of innate immune cells beyond the acute phase. Neutrophils, traditionally associated with tissue injury, also contribute to the resolution of inflammation and initiate key repair processes. Monocytes and macrophages follow a dynamic trajectory, transitioning from pro-inflammatory to reparative states, and play essential roles in debris clearance, angiogenesis, and scar formation. In the early inflammatory phase of acute MI, immune cells such as neutrophils and monocytes are rapidly recruited and activated. While they initially amplify inflammation through the release of pro-inflammatory mediators, their subsequent transition toward anti-inflammatory and reparative phenotypes helps limit tissue damage by clearing necrotic debris from the infarcted area and contributes to the resolution of inflammation. Accumulating evidence reveals a complex crosstalk between neutrophils and macrophages post-MI, with resident macrophages being involved in neutrophil recruitment, and neutrophil-derived signals participating in monocyte recruitment and macrophage polarization, thereby coordinating the spatial and temporal phases of cardiac repair. Understanding how neutrophil-derived mediators influence macrophage responses and whether macrophage-secreted factors reciprocally modulate neutrophil behavior opens promising pathways for developing targeted therapies to limit adverse remodeling following MI. Therefore, this review aims to (i) provide an overview of the roles of neutrophils and monocytes/macrophages in the pathophysiology of myocardial infarction, (ii) explore the mechanisms of communication, particularly via neutrophil-derived secreted factors, that influence monocyte/macrophage function and impact post-MI inflammation, repair, and remodeling, and (iii) highlight the potential therapies interfering with inflammation and neutrophil/macrophage cross-talk.