4 Feb 2021
Imagine if there was a point-of-care solution for high-sensitivity cardiac troponin assays. In this interview, Prof. Louise Cullen, an emergency physician in a major metropolitan teaching hospital in Brisbane, Australia, shares her thoughts on how such a technology could change patient care for those with suspected acute myocardial infarction, and the potential benefits it would have to improve emergency department efficiency.
My name is Louise Cullen. I’m an emergency physician here in Brisbane, Queensland, Australia and I’m a professor at the University of Queensland.
In addition to my clinical work, I’ve been doing research for the last 15 years into ways that we can improve the evaluation of patients who’ve potentially got an acute coronary syndrome and that includes looking at the spectrum of biomarkers that we can incorporate into clinical care.
So, the vast majority of point of care troponin assays that are available internationally are not high sensitivity troponin assays, they’re contemporary assays. And what this means, is that at very low values they are not as precise or not as accurate, and definitely they’ve not got as repeatable test results as that of the lab based highly sensitive troponin assays at the moment.
What this means is that we can’t use them in that same way as doing a single test or even with the serial testing over one, two or three hours – the assay is just not good enough at those early time points for us to rule out a myocardial infarction safely.
Just imagine if we had a point of care fingerstick troponin assay that was available, that was a highly sensitive troponin assay. There’s a number of opportunities in a number of different environments where we could change clinical care.
From an ED perspective, one of the things that we know that we can already do with lab based highly sensitive troponin assays is do that single test and rule out acute myocardial infarction. Now If we can prove that for point of care as well, we can rapidly move people through our EDs.
One of the things people will say, well why would we use a point of care highly sensitive troponin rather than a lab-based assay? When patients come in with an acute coronary syndrome, they’re put on telemetry and monitored very, very carefully and in many institutions the guidelines suggest that we should only take people off telemetry or off monitoring once they are of course symptom free, but that first troponin result has come back as normal or not elevated.
Monitored beds in an ED are precious, and so to get a result rapidly, within 10, 15, maybe even 20 minutes, allows us to step those patients down from high acuity beds and to utilise our resources better.
Now if we can prove that point of care highly sensitive troponin assays, we can do a single test, one and done, those patients also can potentially go and be discharged from the ED or move on to future evaluation if that’s required. So, from an ED setting this is a way to decongest our EDs or to move patients into appropriate areas for care.
Now for many people when a patient comes to the ED, putting a cannula in is just something that happens for everybody. We’ve done some local research having a look at this not only for the pain and distress that it causes patients, but equally the cost and inefficiency of putting in cannulas when you don’t need to.
There’s a myriad of reasons why we should stop doing things just because we do it the same way. But of course, what is dependent on doing just a fingerstick troponin is that we can back it up with the other fingerstick tests that we might need, for example your electrolytes and your liver functions tests as well.
If in the future we’ve got a suite that allows us to do all of these things, then avoiding unnecessary cannulation will not only avoid the discomfort for patients but also the risks for patients and staff, it will improve the efficiency of your ED, and equally there a cost saving by not wasting anything. And so, moving towards this sort of technology – the fingerstick technology – potentially gives us an edge over everything that we are doing at the moment in terms of improving the quality of care that we provide patients.
So, I look forward to the time that we can use point of care blood tests including point of care troponin to change the way that we evaluate patients. It will be the time when we can hopefully get patients home quickly avoiding out lengthily and unnecessary stays in the ED, it will allow us to identify those patients who rapidly need to be brought into hospital and I mean from an ED perspective, decongest our EDs to provide us with more capacity to care for the ever-increasing numbers of patients coming through our doors.
The other opportunity, which is very much you know in the future, will be for point of care assays that are highly sensitive in their characteristics, will be in the hands of our primary care physicians, in the hands of our general practitioners and also in our paramedics, to provide the right care to patients in the right setting.
The University of Queensland
Louise Cullen is an emergency physician in a major metropolitan teaching hospital in Brisbane, Australia, a clinical trialist and outcomes researcher in acute diseases, holding the position of Professor at The University of Queensland and Adjunct Professor at Queensland University of Technology. She is enthusiastically involved in the translation of research by clinical redesign and innovation. As an accomplished acute disease researcher, Prof. Cullen has focused on the diagnosis and management of patients presenting with possible acute coronary syndromes (ACS) in the emergency department (ED). She has been engaged in many international collaborations and has authored over 100 publications in peer-reviewed journals including the NEJM and the Lancet, focused on strategies to improve efficiency, whilst maintaining safety for patients with possible ACS, syncope, heart failure, shortness of breath and atrial fibrillation. More recently, Prof. Cullen has focused on health services research aimed at reducing unnecessary or low benefit care in the ED.