Adrenomedullin as a Biomarker of Heart Failure.

Adrenomedullin (AM) is a vasodilatory peptide originally discovered in human pheochromocytoma tissue. Although AM is highly expressed in the adrenal glands, heart, lungs, and kidneys, vascular endothelium and smooth muscle are thought to be the main source of plasma AM. The AM precursor is processed to AM-glycine, which is then converted to AM-mature through C-terminal amidation. In this process, mid-regional pro-adrenomedullin (MR-proAM) is also produced. Plasma AM, AM-mature, AM-glycine, and MR-proAM levels are all higher in patients with heart failure than healthy subjects in proportional to the disease severity. All molecular forms of AM are prognostic markers for heart failure.