New heart tests speed up diagnosis
New tests could be introduced to drastically reduce the time it takes to diagnose heart attacks.
The two tests measure the levels of cardiac troponin, a protein that is released into the blood when the heart muscle is damaged, often as the result of a heart attack.
Standard tests for cardiac troponin are most accurate when carried out between 10 and 12 hours after the onset of symptoms of a heart attack.
Under current methods two tests are performed to detect any change in troponin levels, which means that for many people they have to be admitted to hospital for observation while the testing is carried out.
But the two new "high-sensitivity" tests can detect lower levels of troponin in the blood than the previous tests, helping doctors diagnose or rule out a heart attack or other cardiac conditions much quicker.
The health watchdog Nice, the National Institute for Health and Care Excellence, has published guidance recommending the use of the two tests and a final decision is expected in October.
Professor Carole Longson, director of Nice's health technology evaluation centre, said that use of the high-sensitivity tests would enable the earlier detection of changes in troponin levels.
She said: "This in turn can allow doctors to rule out a diagnosis of a specific type of heart attack called a non-ST-segment elevation myocardial infarction (NSTEMI) within four hours, if test results are available within three hours of presentation to the emergency department.
"The increased sensitivity of these tests could mean a reduced length of stay for people without raised levels of troponin, and earlier treatment for those with a confirmed NSTEMI."
The new tests would be used alongside traditional electrocardiogram (ECG) tests and an evaluation of a patient's clinical history to diagnose an NSTMEI, a more minor heart attack, because cardiac troponin levels can also be raised in people who do not have coronary heart disease.
Conditions which may cause cardiac troponin levels to be raised include inflammation of the heart muscle (myocarditis), severe infections, and renal disease.
Around 700,000 people go to hospital ever year in England and Wales because of chest pain, according to Nice, while in 2011/12 some 79,433 people were admitted with a heart attack or unstable angina.