An April 2021 study by First Affiliated Hospital of Nanjing Medical University, said,
"We analyzed circulating metabolites in blood plasma samples from cardiac chest pain patients, including heart attack cases and other cardiac chest pain cases, to identify potential markers for heart attack diagnosis and early warning,"
"Such markers could be helpful in confirming heart attack in a timely manner when angiography is unavailable."
"Even after accounting for other cardiac risk factors such as hypertension, smoking and diabetes history, the metabolites deoxyuridine, homoserine and methionine scored highly as potential diagnostic and risk markers of heart attack.”