The new test is much more accurate than the one currently used and could free up doctors’ time and NHS beds.
More than two-thirds of people who go to A&E with chest pains have not suffered a heart attack.
But all of those patients undergo a blood test when they arrive and again three hours later to try and detect damage to the heart muscle.
The current test works by analysing biomarkers – including cardiac troponin. Those with undetectable levels of cardiac troponin are classified as low risk and are discharged from hospital.
:: Heart attack and cancer deaths could be cut by new drug
But up to 85% of all patients fall into an intermediate risk group and require an overnight stay and further blood tests.
Scientists from King’s College London have developed a new test which looks at another biomarker – cardiac myosin-binding protein C (cMyC) – which is more sensitive to damage in the heart muscle.
Levels of cMyC in the blood increase rapidly after a heart attack – to a higher extent than troponin.
The new test – which could be rolled out across the NHS in the next five years – can detect a heart attack much more rapidly and could see those not suffering a heart attack sent home sooner.
The study, on more than 2,000 people in Switzerland, Italy and Spain, was funded by the British Heart Foundation (BHF) and published in the journal Circulation.
It found that the new test doubled the number of patients diagnosed as not having a heart attack.
Experts worked out that just one UK hospital – St Thomas’ in London which carries out 7,800 heart attack tests each year – could save £800,000 a year in reduced admissions and freed up beds.
Dr Tom Kaier, one of the lead researchers, said: “We often see patients in hospital who have to stay for further tests as a result of a mildly abnormal blood test – this is stressful and often unnecessary.
“Our research shows that the new test has the potential to reassure many thousands more patients with a single test, improving their experience and freeing up valuable hospital beds in A&E departments and wards across the country.”