The risk of developing acute coronary syndrome (ACS) significantly increased in patients after receiving mRNA COVID-19 vaccines, according to a report presented at the American Heart Association (AHA) Scientific Sessions 2021, held from November 13 to 15, 2021. The study author concluded that “mRNA [vaccines] dramatically increase inflammation on the endothelium and T cell infiltration of cardiac muscle and may account for the observations of increased thrombosis, cardiomyopathy, and other vascular events following vaccination.”