A delivery system for use with a prosthetic heart valve having a stent frame to which a valve structure is attached includes a shaft assembly including a distal end, an intermediate portion, and a first coupling structure disposed near the distal end and configured to be coupled to a distal end of the prosthetic heart valve via a first tether. A sheath assembly defines a lumen sized to slidably receive the shaft assembly. The delivery system is configured to transition from a loaded state in which the sheath assembly encompasses the prosthetic heart valve to a deployed state in which the sheath assembly is withdrawn from the prosthetic heart valve. The first coupling structure is configured to be manipulated in a first direction to provide a controlled expansion or contraction of the distal end of the prosthetic heart valve.