A device for percutaneously repairing a heart valve of a patient including a self-expanding, stented prosthetic heart valve and a delivery system. The delivery system includes delivery sheath slidably receiving an inner shaft forming a coupling structure. A capsule of the delivery sheath includes a distal segment and a proximal segment. An outer diameter of the distal segment is greater than that of the proximal segment. An area moment of inertia of the distal segment can be greater than an area moment of inertia of the proximal segment. Regardless, an axial length of the distal segment is less than the axial length of the prosthesis. In a loaded state, the prosthesis engages the coupling structure and is compressively retained within the capsule. The capsule is unlikely to kink when traversing the patient's vasculature, such as when tracking around the aortic arch, promoting recapturing of the prosthesis.