A new blood test being developed to diagnose heart attacks could one day be carried out on a simple handheld device, according to researchers.
As a result, this could help staff to make a rapid diagnosis in accident and emergency departments without the need for samples to be sent to a laboratory, said the study authors.
“It is important to work out early who has had a heart attack and who hasn’t”
Their stated ambition is to see the test in use in A&E departments in the UK within the next five years.
The new test uses similar technology to the troponin test, but analyses the level of a protein called cardiac myosin-binding protein C (cMyC).
Levels of cMyC in the blood rise more rapidly after a heart attack and to a higher extent than troponin, so the test can rule out a heart attack in a higher proportion of patients straight away.
An international team, involving researchers from King’s College London, took blood from 776 patients traveling to hospital by ambulance in Denmark and then tested samples for cMyC protein.
In those patients who did experience a myocardial infarction, the protein was present in high enough concentrations 95% of the time for an on-the-spot diagnosis.
Importantly, the cMyC test outperformed the existing troponin test, which was only capable of diagnosing around 40% of patients in this way, said the researchers.
They said this was mainly because troponin takes longer to reach detectable levels in the blood after you suffer a heart attack.
“We’d love to see this used in A&E departments within the next five years”
The researchers now hope to work with industry to create a portable testing device to be used in A&E departments and also in ambulances, where distances to the nearest hospital are long.
A simple handheld device could replace the time-consuming processes involved in sending samples to the hospital labs for analysis, highlighted the researchers.
They noted that over two thirds of people who attend A&E complaining of chest pain have not had a heart attack but will still receive an ECG and a blood test to measure the levels of troponin.
Under current guidelines, patients suspected of having a heart attack are tested for high blood troponin levels as soon as they arrive in an A&E and then again after three hours.
Depending on the type of troponin test used, up to 85% of patients will need to remain in hospital for further tests in order to rule out a heart attack.
The cMyC blood test, developed by King’s College London and tested across Europe, has already been shown to rapidly rule out a heart attack in more people than the standard troponin test.
This could reassure worried patients in A&E departments, free up bed space and save hundreds of thousands of pounds per UK hospital every year, said those behind it.
Dr Tom Kaier, one of the lead researchers from St Thomas’ Hospital in London, said: “It is important to work out early who has had a heart attack and who hasn’t.
“Now that we know that this test is sensitive enough to give an almost immediate heart attack diagnosis, we need to work on developing a testing device,” he said. “We’d love to see this used in A&E departments within the next five years.”
“These initial results with the cMyC test look very promising for patients”
Professor Jeremy Pearson, associate medical director at the British Heart Foundation, said: “Big heart attacks are often easy to diagnose with an ECG but smaller heart attacks, which are more common and also life-threatening, are more challenging.
“The troponin test has been used for around 20 years and is currently the most powerful tool we have for diagnosing such heart attacks, but there is always room for improvement,” he noted.
“These initial results with the cMyC test look very promising for patients, who could be more quickly diagnosed and treated or reassured and sent home,” said Professor Pearson.
“However, further research is necessary before it can be recommended as a replacement for the troponin test,” he added.
The findings from the study, which was part-funded by the British Heart Foundation, were presented today at the British Cardiovascular Society Conference in Manchester.