Every year, more than 200,000 people in Germany suffer a heart attack. This is caused by blocked coronary arteries. As a result, part of the heart muscle is no longer supplied with sufficient blood and oxygen; the tissue dies within a few hours and forms scar tissue. Severe heart failure (cardiac insufficiency) is a possible consequence.

Unlike the liver, the heart of an adult human is barely capable of regenerating. However, it is able to initiate repair processes. Monocytes—white blood cells from the bone marrow and spleen—are involved in this. In the heart, these immune cells mature into macrophages (scavenger cells), remove the dead heart muscle cells and promote healing of the infarct.