What is the new heart attack blood test?
Every year, around one million visits to hospital are prompted by chest pains – but now a new test is expected to be able to give an immediate all-clear to the majority of people who are not at risk of a heart attack.
Most people will recognise that chest pains could be a warning sign of a heart attack. Some may know that dizziness, shortness of breath and cold sweats are other signs. However, as all these symptoms can be attributed to other conditions – some as minor as indigestion – a lot of worry can be caused for nothing. This is why accurate tests are so important.
What are the current tests?
EKG (Electrocardiogram) – records the heart’s electrical activity. The speed the heart is beating and any irregular rhythm can indicate whether the patient has heart disease and any signs that they are having or have previously had a heart attack.
Coronary Angiography – dye is introduced into the patient’s bloodstream and an X-ray measures how it spreads through the coronary arteries, showing any blockages.
Blood tests – measure the amount of certain proteins in the bloodstream. These are released in higher quantities when heart muscle cells die during a heart attack.
What is the new test?
The new test is a simple, high-sensitivity blood test that can detect far lower levels of the protein troponin in the patient’s blood than current tests.
Details of the test, which was funded by the British Heart Foundation and trialled on 6,304 patients based in Scotland and the United States, were announced this month in The Lancet magazine.
Around two-thirds (61%) of those tested were found to have a concentration of troponin below five nanograms per decilitre, which meant that they were considered at very low risk of having a heart attack at the time of the test and within the next 30 days. The results are considered 99.6% accurate.
What are the benefits?
The first and most important benefit is that the test could bring immediate peace of mind to a significant number of patients, who could be sent home straight after the test results. At present they have to wait up to 12 hours for a second test to give them the all clear.
Second, it would free up hospital beds that are currently used for these patients while they wait for their results.
Finally, as the test will cost less than £10 per patient, it should reduce hospital costs in the long run.
Some physicians have said that further research is needed before the test is widely adopted and potentially ill patients are discharged from hospital. However implementation of the test in routine clinical practice should allow its safety and effectiveness to be measured on a wider basis.