Relaxin' the Heart: A Novel Therapeutic Modality.

The peptide hormone relaxin has traditionally been linked to the maternal adaptation of the cardiovascular system during the first trimester of pregnancy. By promoting nitric oxide formation through different molecular signaling events, relaxin has been proposed as a pleiotropic and cardioprotective hormone in the setting of many cardiovascular diseases. In fact, preclinical studies were able to demonstrate that relaxin promotes vasodilatation and angiogenesis, ameliorates ischemia/reperfusion injury, and regulates extracellular matrix turnover and remodeling. In the RELAX-AHF phase 3 clinical trial, serelaxin (recombinant human relaxin) was shown to be safe, and it exerted survival benefits in patients with acute heart failure. RELAX-AHF-2 is currently ongoing, and it aims to address a larger population and evaluate harder clinical outcomes. Besides heart failure, acute myocardial infarction, peripheral arterial disease, and stable coronary disease could be target diseases for treatment with serelaxin in future clinical trials.