Pole vault clot shot victim?

Never heard of this person, but now I have.
What the hell are “medical complications”?

Shawn Barber, the Canadian pole vault record holder and 2015 world champion, has died from medical complications. He was 29. Barber died Wednesday at home in Kingwood, Texas, his agent, Paul Doyle, confirmed to The Associated Press. A cause of death was not yet known. Barber had been experiencing health issues.

Source: Canadian world champion pole vaulter Shawn Barber dies at 29 from medical complications