Transcatheter heart valve delivery system with reduced area moment of inertia

A method of loading a transcatheter delivery system with a prosthetic heart valve having a stent frame and a valve structure assembled to the stent frame and forming at least two valve leaflets, the prosthetic heart valve being radially self-expandable from a compressed arrangement to a natural arrangement, the method comprising:

• receiving a delivery system including:
• an inner shaft assembly including an intermediate portion forming a coupling structure,
• a delivery sheath assembly defining a lumen sized to slidably receive the inner shaft assembly and including a shaft and a capsule extending distally from the shaft, the capsule including a distal segment and a proximal segment, wherein an outer diameter of the distal segment is greater than an outer diameter of the proximal segment;
• and an axial length of the distal segment is less than an axial length of the stent frame;
• coaxially disposing the prosthetic heart valve over the inner shaft assembly such that a proximal region of the prosthetic heart valve is adjacent the coupling structure;
• and
• compressing the prosthetic heart valve to the compressed arrangement over the inner shaft assembly, including disposing the capsule segments over the prosthetic heart valve and crimping the prosthetic heart valve into engagement with the coupling structure to achieve a loaded state;
• wherein the loaded state includes the distal segment encompassing and contacting a distal region of the prosthetic heart valve and the proximal segment encompassing and contacting a proximal region of the prosthetic heart valve;
• wherein the prosthetic heart valve is entirely compressibly retained within the proximal and distal segments.