These clots have been discussed for a long time. There are many videos of Morticians talking about them and showing them as well. I thought everyone knew about these clots. They have pulled some that are multiple feet long.
I asked Vermont Lt, who works in the medical field, if that video was real, but I don't think he ever looked at it.
That message was so long ago, I don't know how I can find the link to it now, but it was creepy as hell.
It literally shows a surgeon cutting open an artery and pulling this stuff out, while the heart is right there beating.