Scientists from King's College London have developed a new blood test that is more sensitive in detecting damaged heart muscle caused by a heart attack.
In a paper published today in the journal Clinical Chemistry, the team investigated how many heart muscle cells needed to die before they could be detected in the blood stream.
Currently, patients with chest pain are responsible for 2.2 million admissions to Emergency Departments every year. Of those suspected of having suffered a heart attack, only a small proportion are shown as having diagnostic changes on a heart trace or ECG. This means that their assessment is reliant on the use of blood tests measuring biomarkers such as cardiac Troponin (cTn) to exclude a heart attack.
Troponin is a heart muscle protein released upon injury and can be detected after heart attacks or heart muscle inflammation. As a result, doctors are able to rule-out heart attacks with a single blood test, as patients with undetectable levels of cardiac Troponin are classified as low risk and are immediately discharged.
However, in a further study of over 4,000 patients at St Thomas' Hospital, scientists at King's (part-funded by the British Heart Foundation) found that 47% fell into the intermediate risk group, requiring an extended period of observation and further blood tests. Indeed, this is not without risk - patients in this group are frequently treated with blood-thinning medication that increases the risk of spontaneous bleeding. The team found that patients are frequently admitted overnight which poses a medical, psychological and social burden and becomes a stressful, often unnecessary experience for the patient.
Using donated human heart muscle tissue, the teamf found that between 3-9 milligram / 0.001% of the entire human heart had to undergo cell death to be detectable in the blood stream. However, their new blood test showed that cardiac myosin-binding protein C was found to be even more sensitive, detecting 0.07 mg / 0.00002% of damaged heart muscle.
"This has the potential to transform the way we diagnose heart attacks in the 21st century," said author Dr Tom Kaier, Specialist Registrar in Cardiology at King's College London and BHF-funded Clinical Research Fellow.
"We know there has not been a reduction in the number of overnight admissions of patients, despite using the best blood tests currently available. We are at looking at improving the experience of patients by developing new and more sensitive blood tests that could help doctors assess the amount of damage quickly and avoid patients being admitted overnight, unless truly necessary."
Professor Sir Nilesh Samani, Medical Director at the British Heart Foundation, said: "This new test could transform the way we diagnose heart attacks, improving the sensitivity and ensuring that heart attacks are not missed when troponin levels in the blood are extremely low. We now need more research to find out whether this test is effective and affordable.
"Over a million people attend A and E with chest pain every year in the UK. The main challenge for doctors is identifying who is having a heart attack, so that people can be treated quickly and effectively. It's also important that we can quickly and confidently rule out a heart attack in people with chest pain from other causes. If found to be effective, this new approach could ensure thousands of patients get life-saving treatment more quickly, while reducing the burden on the NHS."
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Notes to editors:
1. About King's College London
King's College London is one of the top 25 universities in the world (2016/17 QS World University Rankings) and among the oldest in England. King's has more than 27,600 students (of whom nearly 10,500 are graduate students) from some 150 countries worldwide, and some 6,800 staff.
King's has an outstanding reputation for world-class teaching and cutting-edge research. In the 2014 Research Excellence Framework (REF) King's was ranked 6th nationally in the 'power' ranking, which takes into account both the quality and quantity of research activity, and 7th for quality according to Times Higher Education rankings. Eighty-four per cent of research at King's was deemed 'world-leading' or 'internationally excellent' (3* and 4*). The university is in the top seven UK universities for research earnings and has an overall annual income of more than £684 million.
For more information, please visit King's in brief
2. This work was supported by funding from the Medical Research Council, Guy's and St Thomas' Charity, British Heart Foundation and the UK Department of Health through the National Institute for Health Research Biomedical Research Centre award to Guy's & St Thomas' National Health Service Foundation Trust.
3. Guy's and St Thomas' provides more than 2.3 million patient contacts in acute and specialist hospital services and community services every year. As one of the biggest NHS trusts in the UK, with an annual turnover of more than £1.3 billion, we employ around 15,000 staff. http://www.guysandstthomas.nhs.uk
4. The Medical Research Council is at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers' money in some of the best medical research in the world across every area of health. Thirty-one MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed. Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. http://www.mrc.ac.uk
5. About the NIHR Biomedical Research Centre at Guys and St Thomas' NHS Foundation Trust and King's College London
The National Institute for Health Research (NIHR) Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London is one of the first five (of 11) biomedical research centres in England is funded by the National Institute of Health Research to help establish the UK's translational biomedical research infrastructure. With embedded world class core facilities, a range of hosted research organisations and partnerships with industry, this represents the foundation for London's premier biomedical cluster.
In 2016 the National Institute for Health Research (NIHR) announced a new award of £64.4 million to allow Guy's and St Thomas' and King's College London to fund the Biomedical Research Centre for five more years (2017-2022). For more information visit http://www.guysandstthomasbrc.nihr.ac.uk/
Journal
Clinical Chemistry