Background
After myocardial infarction (MI) a local inflammatory reaction clears the damaged myocardium from dead cells and matrix debris at the onset of scar formation. The intensity and duration of this inflammatory reaction are intimately linked to post-infarct remodeling and cardiac dysfunction. Strikingly, results with standard anti-inflammatory drugs worsens clinical outcome, suggesting a dual role of inflammation in the cardiac response to injury. Cardiac stem cell with different stem or progenitor cells, e.g. mesenchymal stem cells (MSC), was recently found to have beneficial effects, mostly related to paracrine actions. One of the suggested paracrine effects of cell is modulation of the immune system.

Scope of review
MSC are reported to interact with several cells of the immune system and could therefore be an excellent means to reduce detrimental inflammatory reactions and promote the switch to the healing phase upon cardiac injury. This review focuses on the potential use of MSC for post-MI inflammation. To understand the effects MSC might have on the post-MI heart the cellular and molecular changes in the myocardium after MI need to be understood.

Major conclusions
By studying the general pathways involved in immunomodulation, and examining the interactions with cell types important for post-MI inflammation, it becomes clear that MSC results might provide a new therapeutic opportunity to improve cardiac outcome after acute injury.

General significance
Using stem cells to target the post-MI inflammation is a novel which could have considerable clinical implications. This article is part of a Special Issue entitled Biochemistry of Stem Cells.

Highlights
► The immune response after MI is intimately linked to long term cardiac outcome. ► Neutrophils and macrophages play important roles in post-MI inflammation. ► Stem cells can modulate the immune response both in vitro and in vivo. ► MSC could be used as for inflammation after acute cardiac injury.