I could be wrong but I think angioplasty is where they insert a balloon like contraption into your arteries and blow it up to release the plaque buildup within your arteries, therefore preventing a possible complete blockage leading to heart attack/stroke.
I didn't bother wikipedia'ing it.
On a side note I'm researching a Tgf-beta which is a growth factor that when active seems to inhibit inflammation. I just saw a paper put out just recently in Circulation, a really good cardiology journal talking about how artherosclerosis buildup can also be because of Tgf-beta. In otherwords, due to cell-signaling, and therefore through genetics, atherosclerosis is largely due to genetics as well.