A new study has found that cross-sex hormones used by transgender people to treat gender dysphoria are correlated with dramatically increased risks of stroke, heart attack, and blood clots .

"Cardiovascular Outcomes in Gender Dysphoric Patients Undergoing Hormone Replacement Therapy," conducted by lead author Dr. Ibrahim Ahmed, who is a third-year resident at Mercy Catholic Medical Center in Darby, Pennsylvania, found that transgender people who had taken cross-sex hormones experienced "nearly seven times the risk of ischemic stroke (a blockage in a vessel supplying blood to the brain), nearly six times the risk of ST elevation myocardial infarction (the most serious type of heart attack) and nearly five times the risk of pulmonary embolism (a blockage in an artery in the lung), compared with people with gender dysphoria who had never used hormone replacements."

Due to the study's findings, researchers are suggesting that there is a need for increased screenings and counseling before beginning hormone replacement therapy.

The American College of Cardiology announced Thursday that Ahmed will present the study and its findings on Sunday, March 5, during its ACC23 conference.

"It's all about risks and benefits. Starting transitioning is a big part of a person's life and helping them feel more themselves, but hormone replacement therapy also has a lot of side effects—it's not a risk-free endeavor," said Ahmed in the press release .

"Looking at a person's medical and family history should definitely be part of the screening protocol before they even start hormone replacement therapy," Ahmed further claimed. "It is also important that people considering this therapy are made aware of all the risks."

Researchers on the study acknowledged that both estrogen and testosterone are known to increase the proclivity for blood to clot. They cede that this may explain the cardiovascular and clotting incidents.

Notably, while hormones were associated with higher risks of cardiac and clotting events, it wasn't associated with a higher rate of death, per the study.

In conducting the study, the researchers used a national database of hospital records to look back at the rates of cardiovascular events in more than 21,000 people with gender dysphoria, 1,675 of whom used hormone replacement therapy.