A new scientific statement released by the American Heart Association this week is warning of potential negative cardiovascular dangers associated with using marijuana — as well as underscoring the need for randomized controlled studies of the drug.

The paper, published in the AHA’s journal Circulation on Wednesday, is a 22-page analysis of the existing research on marijuana consumption, which outlines both the risks and potential benefits of the drug. Dr. Martha Gulati, chief of cardiology for the University of Arizona College of Medicine and editor in chief of the American College of Cardiology’s website, CardioSmart.org, says it’s an important overview. “It’s not guidelines per se, but it’s a statement on what knowledge we have to date relating marijuana to cardiovascular health,” Gulati tells Yahoo Life. “Because we often do get asked this question in patients who have heart disease if it’s OK for them to use marijuana.”

To help unpack the paper’s main points, here’s what you need to know.

Marijuana use could increase the risk of arrhythmias and stroke

Throughout the study, the authors emphasize that conclusive evidence on how marijuana affects the heart is lacking. But they note that tetrahydrocannabinol (THC), the psychoactive ingredient in cannabis, may be dangerous for certain individuals. [Read more at Yahoo!]