Heart cath and blockages

Sorry, this is not about books, but I just want to mention that my oldest dtr (57) had a heart cath today and they found 3 blockages. They stented 2 and left the other one to do in about a month.  Why, I do not know, would they do that?  That makes my second dtr. to have heart blockages, but their mother (me) and their father both had heart caths, by-pass surgery, stents, atrial fib, etc.

JOY