This is not an official warning from the "American Heart Association".
This is not even an article published in a peer review journal of the "American Heart Association".
The "American Heart Association" made a conference and later published all the abstracts of the talks/posters https://www.ahajournals.org/toc/circ/144/Suppl_1 This is in the section "ARTERIOSCLEROSIS, THROMBOSIS, VASCULAR BIOLOGY (222)"
Note that in many conferences the peer review process is very week or inexistent. It the abstract barely makes sense, they will allow the talk and publish the abstract later. (Been there, done that, my talk was not even the worse one.) (Also, during the peer review they don't verify the data. They thrust the author. It's very different from some CS conferences where they may ask for a github repo.)