OR-1896-d3 is the deuterium labeled OR-1896 (HY-135746). OR-1896 is an active long-lived metabolite of Levosimendan. OR-1896 is a highly selective phosphodiesterase (PDE) III isoform inhibitor and a powerful vasodilator. OR-1896 can open ATP-sensitive K+ channels and has Ca2+-sensitizing effect. OR-1896 mitigates cardiomyocyte apoptosis, cardiac remodeling and myocardial inflammation[1].