I had a drug eluting stent two years ago in my Circumflex and stayed on Plavix for 12 months which is the standard time. A recent angiogram revealed the stent is doing a great job with no sign of any more disease. Drug eluting stents tend not to disease.
I have three drug eluting stents in the LAD, two non-drug eluting stents and three drug eluting stents in my RCA. I stayed on Plavix for 1.5 years after the last stent, and been off Plavix for over a year with no restinosis. I do exercise daily, take Vytorin, 81mg aspirin, and follow a healthy heart diet very carefully. So far, no problems with restenosis, but believe me, I think about it every day.
I suspect your question would be answered with lots of questions from a doctor, such as what is your stress level, are you exercising, is there a diabetes factor, etc. I'm not sure that there is a clear answer to your question.