I have two heart stents. I got them in 2005, I died on the table,?

naturally my life was saved. I thank God and the Dr. His name is Dr. Messenger what a coincidence hu? My question is, how long to these stents last? I have been on heart meds since, blood thinner and asperin. Do they go bad? I understand about diet, exercise etc. I just want to know, do they wear out and just go bad? Thanks in advance. Is there a time frame for these things? I know a lot of ?'s sorry, but I am sure you all will know and understand my question.