An implantable prosthetic device can include a hybrid frame movable between a radially compressed configuration and a radially expanded configuration. The hybrid frame can include a mechanically-expandable first sub-frame comprising a plurality of struts pivotably coupled to one another, and a plastically deformable second sub-frame coupled to the first sub-frame. When the hybrid frame is in the expanded configuration, the second sub-frame can be configured to resist radial compression of the frame.