The new test is much more accurate than the one currently on offer and could free up doctors’ time and NHS beds if rolled out nationally.
It is thought that more than two-thirds of people who go to A&E with chest pain have not had a heart attack.
At present, all of these patients undergo a blood test when they arrive at A&E and again three hours later which is designed to detect damage to the heart muscle.
The 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.
However, thousands of patients fall into an intermediate risk group - up to 85 per cent of all patients - and require an overnight stay and further blood tests.
Scientists from King’s College London have now developed a new test that looks for another biomarker - cardiac myosin-binding protein C (cMyC) - which is found to be even more sensitive at detecting damage to the heart muscle.
Levels of cMyC in the blood increase more rapidly after a heart attack, and to a higher extent, than troponin.
The new test - which could be rolled out across the NHS in the next five years - can therefore lead to a much more rapid diagnosis.
It enables those not suffering a heart attack to be sent home sooner, and may also pick up heart attacks not detected by the current test.
The latest study on more than 2,000 people at hospitals in Switzerland, Italy and Spain was funded by the British Heart Foundation (BHF) and published in the journal Circulation.
The results showed that compared to the troponin test, the new test doubled the number of patients found not to be having a heart attack.
Experts calculated 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 by reducing admissions and freeing up beds.
Across the entire NHS, the figure will be much higher, although the BHF could not give an estimate of how much in total could be saved.