Abstract: A mechanical heart valve assembly includes an orifice coupled with a stiffening ring and sewing cuff by a lock wire. The lock wire is made from a super-elastic material, e.g., a nickel-titanium alloy, and pre-formed into a C-shape. The lock wire is inserted between the orifice and stiffening ring by piercing the sewing cuff that surrounds the ring, and passing the lock wire into a window in the stiffening ring and into the aligned lock wire grooves on the stiffening ring and orifice. Once seated in the lock wire grooves, the lock wire retains its C-shape, providing a secure coupling between the orifice and stiffening ring.