The angiogram (catheter via groin or wrist area) is still considered the "golden standard".
It gives the best information about the condition of the coronary arteries (x-ray images from different directions but also arterial pressure drop in case of stenosis, etc.
It also allows for direct therapy (ballooning, stenting).
For most cardiologists an angiogram is a routine examination with little risk. Complications occur in about 1%. Most of them are bleeding issues after the procedure and are normally easy solved.
A CT angiogram carries almost no risk but provides less (reliable) information..