Endoprosthesis for delivery in a body lumen is provided. The endoprosthesis includes an annular element defined by a set of interconnected strut members, each strut member including a first end and a second end. The first end of selected pairs of circumferentially-adjacent strut members of the annular element are interconnected to define apices proximate a first longitudinal side of the annular element and the second end of selected pairs circumferentially-adjacent strut members are interconnected to define apices proximate a second longitudinal side of the annular element. At least one of the selected pairs of circumferentially-adjacent strut members has a modulator disposed proximate the apex defined there between, the modulator having a first mode to allow expansion of the annular element from an unexpanded configuration toward an expanded configuration and a second mode to resist contraction of the annular element from the expanded configuration toward the unexpanded configuration.