A €5 blood test which identifies whether people with chest pains are at risk of a heart attack could improve treatment at A&E departments worldwide, researchers claim.
A global study of nearly 23,000 people found the test accurately ruled out the risk of a heart attack in almost half of all those arriving at hospital emergency departments with chest pains.
Results can be obtained in 20 minutes and updating international guidelines on using the test on arrival at hospital could save millions of patients from having further tests and cut costs, researchers said.
Chest pain is a common reason for attendance at A&E but fewer than one in five of those affected are having a heart attack.
In early studies, the check accurately predicted the risk of heart attack in more than 6,000 patients admitted to hospital in Scotland.
The test measures levels of the protein troponin, released by damaged heart cells, in the blood and the higher the level found the more likely it is the patient has had or is likely to have a heart attack.
Now, researchers have pinpointed a threshold level of troponin in the blood, below which patients are unlikely to have had a heart attack and are at very low risk of experiencing one in the next 30 days.
Their latest research analysed almost 23,000 people at 19 hospitals in Europe, North America and Australasia, who received the test after arriving with chest pains.
Dr Andrew Chapman, a research fellow at Edinburgh University which led the study, said: "We believe the findings of this worldwide study will provide national and international guidelines committees with the evidence they need to recommend the use of troponin testing to rule out heart attacks much earlier in the emergency department.
"This has major potential to improve the safety and efficiency of healthcare delivery, at a time of increasing financial pressures on our National Health Service."
The research is published in the Journal of the American Medical Association.