Chris, where exactly do you mean? They went in via the groin, and it's like when they take a blood test, and it left no scar tissue (I've had it done twice).
Or do you mean in the heart itself? I don't know about that. When I had my angiogram five years ago, they put in two stents -- regular stents, not the ones that emit medication -- and I have tests done twice a year and everything is absolutely fine. I also have a stent in my neck (carotid artery) and it is also examined by doppler every so often, and it is completely clear. No one has ever mentioned the possibility of any scar tissue, not inside the heart and not in the carotid artery.
That's my personal experience, for what it's worth! Well, for me it has been worth everything, because my life has been saved! I am so grateful to the doctors.
Love, Esther