A prosthesis is disclosed including an expandable frame having a first region and a second region coupled to one another. The first region includes a transition segment and a flex segment. The stent members of the transition segment have proximal and distal apices arranged in a peak-to-peak relationship with one another. At least a portion of proximal and distal apices of the transition segment remains uncoupled to one another. The flex segment includes a stent member having proximal and distal apices arranged in a peak-to-valley relationship with the transition segment. Longitudinal tie bars are intermittently coupled between apices the flex segment and the transition segment at coupling joints. The coupling joint is located where the proximal and distal apices of the stent members of the transition segment remain uncoupled to one another. The transition and flex segments may form an alternating pattern. A flareable proximal portion may be included.