A quick and cheap blood test could help doctors to spot people at high risk of death following a suspected heart attack, according to research funded by the British Heart Foundation.
In the largest study of its kind, researchers at the National Heart and Lung Institute, Imperial College London, in collaboration with the National Institute for Health Research (NIHR) Health Informatics Collaborative (HIC), found that measuring levels of high sensitivity C-reactive protein (CRP) – a sign of inflammation – in the blood of people after a heart attack can better identify if they are at risk of dying in the next three years.
The blood test – already used in hospitals to diagnose other conditions – could be used to streamline how patients are treated following a suspected heart attack. Those identified as at high risk of death could be given more aggressive treatment and monitored more closely, while those identified as low risk could be given reassurance and sent home.
Currently, when doctors think a person has had a heart attack, they perform a blood test for troponin, a protein that is released into the blood stream when the heart is damaged. Now, scientists have found that measuring CRP levels at the same time provides a more detailed picture to show which patients are at high or low risk.
The team used data gathered by the NIHR HIC from over 250,000 patients who were admitted to hospital with a suspected heart attack. Normally the level of CRP in the blood is 2 mg/L or under, but they found a mildly raised measurement of 10-15 mg/L CRP in those with a positive troponin test predicted a greater than 35% chance of death three years later.
This discovery also opens the door to more targeted treatment for heart attack patients who have life-threatening inflammation as indicated by a slightly raised CRP reading. Doctors could consider giving these people more intensive therapies.
Some anti-inflammatory drugs such as colchicine, have already been found to be effective against atherosclerosis – the build-up of fatty deposits in the arteries that increases your chance of a heart attack. Dr Ramzi Khamis now hopes to test colchicine specifically in patients with increased CRP levels to determine whether it could be an effective treatment to increase the survival after a heart attack.
Dr Ramzi Khamis, BHF Intermediate Clinical Research Fellow and consultant cardiologist at the National Heart and Lung Institute, Imperial College London said: “Testing for this biological ‘red flag’ at the same time as other hospital tests identifies those more vulnerable patients who should be receiving closer medical attention. Importantly, we hope with more research, we can be successful in developing new therapies that specifically combat inflammation to improve outcomes in heart disease.
Dr Amit Kaura, BHF Clinical Research Fellow and lead researcher for the NIHR HIC at Imperial College London added: “This study shows that analysing large sets of real-world clinical data can cast light on patterns of disease and identify those at high risk of dying. We hope to use this knowledge to guide our clinical decision making in treating patients with suspected heart attacks."
The results of the study were published in PLOS Medicine.
