OR-1896-d3 is the deuterium-labeled form of OR-1896, which is the active, long-lasting metabolite of Levosimendan. It acts as a highly selective phosphodiesterase (PDE III) inhibitor and serves as a potent vasodilator. OR-1896 is capable of opening ATP-sensitive K+ channels and demonstrates Ca2+ sensitizing effects, which help reduce apoptosis in myocardial cells, cardiac remodeling, and myocardial inflammation.