I fully agree with Steve. Clinical augmented reality is still in its infancy, there are too many limitations, which make it hard to find applications that make sense and feasible to implement. On the other hand, virtual reality is here, it is very powerful and inexpensive already, and there are already many applications where it makes a difference.
Anyway, if you are determined to go forward with augmented reality and can accept limitations of using surface rendering as visualization (as opposed to volume rendering), then you can use Slicer to do all the processing and use a very simple Unity-based viewer on the HoloLens or MagicLeap to view these surface meshes.
You can create surface mesh (STL, OBJ, …) file from cardiac CT as shown here:
If you just need to visualize displacement due to cardiac motion then it may be enough to segment only a single phase, then use Sequence Registration extension to compute displacement field over the entire cardiac cycle, and apply the transformation sequence to your segmentation to get a full 4D segmentation. If you need higher-fidelity then you need to segment several phases manually (you might reuse initial seeds from one phase, potentially saving a few minutes of work per phase). See more information in this topic: