A simple blood test could help predict the risk of a heart attack in patients with chest pain.
The test measures levels of troponin, a chemical signal in the blood that indicates heart damage.
Researchers at Karolinska Institute studied more than 8,000 patients who came to the hospital with chest pain-but had undetectable levels of troponin and no sign of reduced blood flow.
Less than one-percent had a heart attack within 30 days.
Researchers said this blood test could help prevent many unnecessary hospital visits but more studies are needed.