A method of treating a diseased cardiac valve can include implanting a valve prosthesis by compressing the valve prosthesis to a compressed state for delivery and expanding the valve prosthesis to an expanded state for deployment. The valve prosthesis can include a valve fixation device having a plurality of struts, a first circumferential row of cells coupled to the struts, and a second circumferential row of cells coupled to the struts. The struts are substantially rigid such that the struts do not change dimensions between the compressed state and the expanded state. The valve prosthesis can also include a plurality of leaflets and a plurality of commissures. The valve is coupled to the valve fixation device such that the commissures are radially aligned with respective struts of the plurality of struts.