https://casehippo.com/apps/symposium/national-kidney-foundation-2020-spring-clinical-meetings/event/gallery/abstracts?abstractId=1620
Look at the tag up-top.
No sign of that on the AJKD website.
If you search for Kalantar (family name of the presenter), you'll get the number 258 that was withdrawn, probably RVX's presentation.
Why is a billion dollar question.