A valve holder configured to be attached to a delivery handle and to a prosthetic heart valve comprising a plurality of commissure posts and a plurality of flexible leaflets connected to the commissure posts, the valve holder comprising: a body having a first end, a second end, and a central axis extending between the first and second ends, the body comprising a first portion at the first end and a second portion at the second end with an outer width that is smaller than an outer width of the first portion, wherein a coaxial bore extends through the body, and wherein a first region of the bore has an engagement portion for engaging the delivery handle; a plurality of arms connected to the first portion of the body and extending axially from the first portion towards the second end of the body; a plunger positioned in the bore of the body, wherein a first portion of the plunger is configured to extend at least partially into the first region of the bore; and a plurality of sutures respectively connected between each arm and the plunger; wherein in a first configuration, the plunger is at a first position where the first portion of the plunger extends into the first region of the bore, the sutures extend substantially radially from the plunger to respective ones of the arms, and free ends of the arms are positioned at a first radial distance from the central axis of the body; and wherein in a second configuration, the plunger is at a second position closer to the second end of the body, at least part of the sutures are displaced by the plunger towards the second end of the body, and the arms are pivoted radially inwardly by the sutures such that the free ends of the arms are positioned at a radial distance from the central axis of the body that is less than the first radial distance to inwardly deflect commissure posts of the prosthetic heart valve that are attached to free ends of the arms. a body having a first end, a second end, and a central axis extending between the first and second ends, the body comprising a first portion at the first end and a second portion at the second end with an outer width that is smaller than an outer width of the first portion, wherein a coaxial bore extends through the body, and wherein a first region of the bore has an engagement portion for engaging the delivery handle; a plurality of arms connected to the first portion of the body and extending axially from the first portion towards the second end of the body; a plunger positioned in the bore of the body, wherein a first portion of the plunger is configured to extend at least partially into the first region of the bore; and a plurality of sutures respectively connected between each arm and the plunger; wherein in a first configuration, the plunger is at a first position where the first portion of the plunger extends into the first region of the bore, the sutures extend substantially radially from the plunger to respective ones of the arms, and free ends of the arms are positioned at a first radial distance from the central axis of the body; and wherein in a second configuration, the plunger is at a second position closer to the second end of the body, at least part of the sutures are displaced by the plunger towards the second end of the body, and the arms are pivoted radially inwardly by the sutures such that the free ends of the arms are positioned at a radial distance from the central axis of the body that is less than the first radial distance to inwardly deflect commissure posts of the prosthetic heart valve that are attached to free ends of the arms.