http://www.sleep-journal.com/article/S1389-9457%2800%2900032...
https://www.gwern.net/docs/melatonin/1996-coren.pdf
https://www.sciencedaily.com/releases/2014/03/140329175108.h...
http://psycnet.apa.org/journals/apl/94/5/1305/?nl=nytnow&em_...
..and many more. You'll note a complete lack of sensationalist articles in the above links.
Keeping DST amounts to self-flagellation. Much like the existence of the penny, it's a thing that has few legitimate reasons to exist and many more legitimate reasons to be burned to the ground.
If you're to the point that losing an hour of sleep triggers a heart attack, DST didn't cause your heart attack. Daylight savings time rescheduled it from Wednesday to Monday.
Edit: I guess that was apparently in the original study, it just doesn't make it into most pop coverage of it.
"The overall number of heart attacks for the full week after daylight saving time didn’t change, just the number on that first Monday. The number then dropped off the other days of the week."
https://www.reuters.com/article/us-heart-daylightsaving/dayl...