Data presented at the British Cardiovascular Society Conference (4–6 June, Manchester, UK) indicate that a novel blood test for diagnosing myocardial infarction could one day be carried out on a simple handheld device, giving a rapid diagnosis in emergency departments without the need for samples to be sent to a lab. A BCS press release reports that the new test uses similar technology to the troponin test but analyses the level cardiac myosin-binding protein C (cMyC) instead.
According to the press release, levels of cMyC in the blood increase more rapidly after a myocardial infarction, and to a higher extent, than troponin. This means meaning that the new test can rule out a myocardial infarction in a higher proportion of patients straight away.
The international team, part-funded by the British Heart Foundation, took blood from 776 patients traveling to hospital by ambulance in Denmark. Researchers based at King’s College London then tested these samples for cMyC protein. In patients who did experience 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.
The researchers, who were funded by the British Heart Foundation, now hope to work with industry to create a portable testing device to be used in UK A&E departments. The test could also be used in ambulances in countries where ambulances have to drive considerable distances to get patients to their nearest hospital. The press release states that a simple handheld device could replace the time-consuming processes involved in sending samples to the hospital labs for analysis.
Under current UK guidelines, people suspected of having a myocardial infarction are tested for high blood troponin levels as soon as they arrive in an A&E, and again after three hours. Depending on the type of troponin test used, up to 85% of people will need to remain in hospital for further tests in order to rule out a heart attack.
The cMyC blood test, developed by a team from 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. Tom Kaier (St Thomas’ Hospital, London, UK), one of the lead researchers, says: “It is important for both patients and doctors to work out early who has had a heart attack and who has not. 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. We’d love to see this used in A&E departments within the next five years.”
Jeremy Pearson, associate medical director at the British Heart Foundation, says: “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. 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. However, further research is necessary before it can be recommended as a replacement for the troponin test.”