A delivery system for use with a prosthetic heart valve having a stent frame to which a valve structure is attached, the system comprising: a shaft assembly including a distal end and a nose cone disposed at the distal end, wherein a coupling structure is disposed near the distal end and configured to be coupled to a distal end of the prosthetic heart valve ; a sheath assembly defining a lumen sized to slidably receive the shaft assembly ; and wherein 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in which the sheath assembly encompasses the prosthetic heart valve to a deployed state in which the sheath assembly is withdrawn from the prosthetic heart valve , and wherein the coupling structure is configured to provide a controlled expansion or contraction of the distal end of the prosthetic heart valve based on longitudinal movement of the distal end of the shaft assembly , characterised in that the coupling structure is slidably attached to the nose cone , and wherein the coupling structure and the nose cone are configured to slide in a longitudinal direction with respect to each other, wherein the nose cone comprises a tip portion and a tubular portion defining a lumen , which is configured to slidably receive the coupling structure , wherein the coupling structure comprises a tubular base portion and a plurality of legs extending from the tubular base portion , and wherein when the coupling structure is positioned within the tubular portion , the tubular portion of the nose cone maintains the coupling structure in the compressed state, which correspondingly compresses the distal end of the prosthetic heart valve , wherein the coupling structure can slide outside of the tubular portion , which correspondingly allows the distal end of the prosthetic heart valve to self expand. a shaft assembly including a distal end and a nose cone disposed at the distal end, wherein a coupling structure is disposed near the distal end and configured to be coupled to a distal end of the prosthetic heart valve ; a sheath assembly defining a lumen sized to slidably receive the shaft assembly ; and wherein 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in which the sheath assembly encompasses the prosthetic heart valve to a deployed state in which the sheath assembly is withdrawn from the prosthetic heart valve , and wherein the coupling structure is configured to provide a controlled expansion or contraction of the distal end of the prosthetic heart valve based on longitudinal movement of the distal end of the shaft assembly , characterised in that the coupling structure is slidably attached to the nose cone , and wherein the coupling structure and the nose cone are configured to slide in a longitudinal direction with respect to each other, wherein the nose cone comprises a tip portion and a tubular portion defining a lumen , which is configured to slidably receive the coupling structure , wherein the coupling structure comprises a tubular base portion and a plurality of legs extending from the tubular base portion , and wherein when the coupling structure is positioned within the tubular portion , the tubular portion of the nose cone maintains the coupling structure in the compressed state, which correspondingly compresses the distal end of the prosthetic heart valve , wherein the coupling structure can slide outside of the tubular portion , which correspondingly allows the distal end of the prosthetic heart valve to self expand. <EOS>