The only thing I would say against this, is what from his 2016 campaign gives you any indication Sanders is the sort of candidate who will cut his losses and think big picture? I think the clear right thing for him to do here is recognize that his having a heart attack in the middle of his primary campaign would make him an extremely risky top-of-ticket pick and the general election would be a referendum on his VP if he were to somehow win, but my gut feeling here is the only way Sanders suspends his campaign and his supporters rally around an alternative (and the politics are more complex than they might seem at first glance, by the way - I haven't seen post-Ukraine numbers but the last polling I saw, a plurality of Sanders supporters named Biden as their second pick) would be if the second heart attack kills him. At which point, and forgive me for making light of this, his supporters will probably just blame Clinton. Were they? I remember SHE tried to brush it under the rug, but Trump pounced immediately and it became a pretty big story, at least until the Comey letter a couple weeks later ate up all the bandwidth. Honestly, I've been a little out of the loop lately, but I feel like Bernie's heart attack is getting a lot less media coverage than Clinton's fainting at a campaign event did, which makes a lot of sense I suppose because Sanders was maybe the third-most likely nominee at the time, while Clinton was the favorite to win the Presidency at the time.