It does seem like some of these IR's should consider trying putting people on ET antogonists systemic drugs just prior to and after balloon angioplasty, for however long it takes the injury to the vein to heal.
Ah... I just figured out why they don't do that. Those IR's are pretty smart!
According to wikipedia at least some of those Endothelin Antagonist drugs have a very nasty side affect: liver damage. One Endothilin A receptor antagonist was recently voluntarily pulled from the market due to it causing fatal liver damage:
Here's the link to the page on endothelin receptor antagonists in general:
http://en.wikipedia.org/wiki/Endothelin ... antagonist