An observational study - statistical correlation, no clinical trial was involved -
does not show a link between the antimalarial drug chloroquine (or its analogue hydroxychloroquine) and benefit in patients with COVID-19. The pool was nearly 15,000, presumably patients with COVID-19, receiving a combination of any of the four drug regimens, compared with 81,000 who did not. They did find a statistical link to risk of more heart issues.
What does that really mean? Despite what you read in the media about how it does not work, and that it "causes" heart attacks, it really only means the drugs need to go into clinical trials.