How are Non-ST segment elevation myocardial infarction (NSTEMI) and acute coronary syndrome (ACS) patients currently identified?
ACS is currently identified through the use of ECGs pre-hospital and the confirmed via a Troponin biomarker test once in the acute setting.
The difficulty with NSTEMI is that it may not show on the ECG and thus requires the Troponin test to confirm a cardiac event.
This presents the potential for delays in treatment and, in a number of settings, the patient being taken to the wrong hospital site, as seen in Leicester or the wrong department, causing further delays to patients receiving specialist care.
Why do some NSTEMI and ACS patients not indicate signs of acute myocardial infarction in ECG testing?
In NSTEMI, the coronary artery is not totally blocked, so whilst an event is occurring and damage is being created, there may be no indication via the ECG.
This presents further problems as without a diagnosis via the ECG, the cause of the pain maybe unrelated to a cardiac event, or may be a result of unstable angina.
What inspired you to look into the use of cardiac biomarkers in the early identification of ACS/NSTEMI?
I was aware of a gap in the current process and in the Leicester area the distance between the Emergency Department in Leicester city and the CCU at Glenfield Hospital on the outskirts.
Without a positive indication being shown on the ECG, the patient is taken to Leicester Royal Infirmary. The Troponin test is then given and a positive result means the patient is transferred to Glenfield.
This is clearly bad for the patient as they do not receive the specialist care as soon as is possible for other types of heart attack.
There are also knock on effects to other patients. Additional patients in ED takes up acute hospital capacity, can impact on handovers between the ambulance service and the acute ED and transfers of patients between hospital sites reduces ambulance service capacity.
What impact do delays in treatment have for patients with cardiac episodes?
1 year mortality risk increases by around 7.5% for every 30 minutes of delay. The immediate result of the delay in treatment is increased myocardial necrosis.
We see patient delaying the call for help, but what we are trying to do here is limit the damage caused following the call from the patient.
What is H-FABP and how can you test whether it is suitable to detect Myocardial Infarctions (MI) in a pre-hospital setting?
Heart-type Fatty Acid-Binding Protein (H-FABP) is a protein released following a cardiac event. This a biomarker that is detectable in the blood in a short period of time, as quickly as one hour.
Suitability for use in identifying ACS has previously been proven and this biomarker is used in other areas of the world in acute settings. It was also recently trialed in the acute setting in the north of England with very good results.
Implementation pre-hospital relies on a small, reliable and cheap method of assessment, which we believe we have. This method of assessment will be trialed in the Leicester area to assess whether we have the required levels of sensitivity and specificity for the pre-hospital environment.
Why does the kit also test for the presence of Troponin-I?
By conducting the double test, sensitivity is increased significantly, which gives the patient the best chance of being identified as having a cardiac event and thus the best chance of receiving the right care, first time.
At what stage is this research currently at?
We are currently moving to gain ethics approval to run a trial in the Leicestershire area.
Why has no one previously used the HFABP biomarker in a pre-hospital setting to identify patients that are suffering from NSTEMI?
I think a lot of people forget that the ambulance service is the first contact for a lot of people. I have identified a number of devices and point of care tests that could be moved forward into the pre-hospital setting with very little difficulty.
The ambulance services has the ability to sit at the centre of the entire health care system, but is often on the edge. By utilising the service’s unique offerings, there is far more that can be done to improve the patient experience and reduce inefficiencies that we see.
You have recently won an East Midlands Health Innovation Award. What impact do you think this will have?
Our success here was fantastic. It has given us credible recognition that we have an innovation that is genuinely seen as a game changer.
By winning this award we have been able to fund the testing kits without impacting on any NHS budget and we can truly see whether this idea has the potential I saw in it back when I first embarked on looking at HFABP.
This is the first biomarker I have looked at and it’s an area that I feel will revolutionise point of care testing.
In our setting, getting more biomarkers that can use whole blood, saliva or sweat would mean we could a lot of diagnosis work before a patient even arrives at hospital, meaning patients receive appropriate care, faster whilst reducing costs to the acute hospitals.
What do you think the future holds for identifying patients suffering from NSTEMI?
I think as time goes on, there will radical changes and improvements in the identification of all cardiac events and the wider use of biomarkers to make fast and accurate diagnosis’ will be the first step.
The disposable test we are using here costs 5 euros, compared to an ECG enabled defib at over £15k. The potential to deliver better solutions at a far lower cost is huge and goes far wider than just the identification of NSTEMI.
Where can readers find more information?
For information about what we are doing, they can contact me directly.
About Peter Mason
I graduated in 2001 with a degree in Business Management before joining the NHS as a Staffing Co-ordinator. I spent most of my career in Human Resources working for several organisation in both the public and private sector gaining both a post graduate degree in Human Resources Management and Chartered status of the CIPD.
Since 2007, I have worked for East Midlands Ambulance Service NHS Trust, moving into a service improvement role in 2009. Since that time I have delivered a number of service changes that have received national recognition including 2 BMJ awards, an Ambulance Service Institute Award, a national Patient Safety Award and a national Local Government Award along with the most recent recognition at the Innovation in Health Awards.
I am currently completing my MBA and an MSc in Healthcare Management under the Leadership Academy’s Elizabeth Garrett Anderson Programme and have been shortlisted for Innovator of the Year at the East Midlands Leadership Academy Awards.