Anchor for an implantable sensor

An anchor for an implantable medical device, for example, and implantable physiologic sensor, includes a proximal hub portion, an intermediate portion extending radially and distally from the hub portion, and a distal portion extending distally from the proximal portion and adapted to engage an inner surface of a target vessel for securing the implantable medical device therein. The anchor can assume a collapsed configuration for delivery through a catheter, and an expanded configuration for fixation within the vessel once deployed. The intermediate portion extends from the proximal portion at an oblique angle, allowing the anchor to be retracted and re-collapsed within the delivery catheter after initial deployment, if re-positioning or removal of the implantable medical device is necessary or desired.