Yes, I've heard nothing about people getting tested for this before being put on Plavix. There are such large numbers of us, surely some of us are poor metabolizers. I feel that the docs may not be taking the situation seriously enough.
There are three parts to the procedure, as I understand them: first finding all the CCSVI (a challenge and a reason to go to an experienced doc); second effectively treating all the CCSVI (a challenge and a reason to go to a doc who uses the more aggressive ballooning methods); third keeping the blood flow open in the months post-procedure (a challenge and a reason to go to a local doc as well as a doc who prescribes adequate anticoagulation and who responds immediately with a follow-up doppler and second procedure if restenosis is found).
When I say the docs are not taking the situation seriously enough, I mean they are treating patients without having adequate follow-up in place. This puts patients at risk at having their jugular or azygous vein clot over and be lost. If it was the carotid artery and we dropped dead when it was lost, the docs would take that very seriously. They would not be treating and releasing the way they are. Since it's the jugular, it puts us at risk of long painful neurodegenerative decline if it clots over. These veins are important, you cannot embrace the CCSVI theory without embracing this too.
On a separate note, I found a Plavix animation, but can't tell the difference from it between Plavix and the Heparin chart linked above, even though one is antiplatelet and the other anticoagulant.
Here it is anyway, it's down on the left where it says, "Click here to see animation":