I am not a doctor, but it depends on what is causing the restenosis. If her artery is rejecting the stent and closing around the stent, I am not sure what to do.
But I have found relief from my heart problems using Angioprim which clears out the calcium deposits, and does it much faster than anything else I have tried. If her arteries are clogging up with calcium deposits, I would recommend Angioprim highly.