Threshold or guidance for angioplasty

Tomorrow, i undergo an angiogram that was ordered after a marginally result during a treadmill stress test. I am about 10 lbs over weight (index~27), have ldl of 160 (under lipid therapy now), and have chest discomfort when heart rate exceeds 130 bpm. However, the discomfort dissipates rapidly after I belch and will rebuild if exercise continues. A series of gastro tests found no abnormal conditions. I do have spiking blood pressure at exercise and have been under beta blocker for 5 years. Finally, i am anaphylactic to iodine from an adolescent IVP, but i am being premedicated: there is some increased risk in doing this procedure again.

Question: what are the current guidelines for degree of stenosis that warrants a stent? Any guidance in this case? Can the stability of the plaque be assessed and if so, does that guide therapy?

[Encephalomalcia]

Doctors opinions may differ, but what I have found is usually around 70 percent blockage, a stent is needed.  Sometimes an artery will spasm with only 30 percent blockage and in that case a stent is also needed to prevent the spasming and chest pain (which can be as severe as a heart attack).  Hope all goes well for you tomorrow.  An angiogram does give the answers that are needed more than any test will.  Take care and get some sleep.