Commissure locking member

An implantable prosthetic device, comprising:

• a radially expandable and compressible frame, the frame comprising an inflow end portion, an outflow end portion, and a commissure post comprising a first set of lateral extensions disposed adjacent an outflow end of the commissure post and a second set of lateral extensions spaced apart from the first set, each lateral extension comprising an inner bore;
• a commissure attachment member having a first set of arms each extending into a respective inner bore of a lateral extension of the first set of lateral extensions and a second set of arms each extending into a respective inner bore of a lateral extension of the second set of lateral extensions such that the commissure attachment member is restrained from movement relative to the commissure post in the radial and axial directions;
• and
• wherein the commissure attachment member is configured to couple a portion of a valvular structure to the commissure post.