By John Pickering 29/03/2021

Early last year the expected influx of patients with COVID-19 to emergency departments (ED) in New Zealand required rapid preparation.  Many questions needed answering quickly – such as, where will we put all the patients? How will we separate highly likely COVID-19 patients from less likely COVID-19 patients?  How will we allocate staff and keep them safe?

One of the two most common presentations to the ED are people who think they may be having a heart attack – chest pain patients.  I got the call to ask if there was a way we could speed up assessment of these patients and identify who could safely go home earlier.  This was a challenge, as Christchurch was already one of the leading hospitals globally for accelerated diagnostic pathways for possible heart attacks.

My job was to go back to our research data to try and extend and improve the identification of low-risk patients.  But I was only one cog in the wheel led by ED specialist Dr Martin Than.   He along with the Cardiologists were also exploring ways to minimise “double-handling” of patients by more than one speciality.  Finding ways to both reduce the time a patient spends in the ED and to reduce the number of nurses and physicians who come into contact with an individual patient would reduce the risk of cross infection, and could free staff time for other patients.

The accelerated diagnostic pathway (ADP) for chest pain comprises three components, an electrocardiogram (measurement of the electrical activity of the heart), a risk assessment score (called EDACS) based on symptoms, demographics and medical history, and measurements of a blood biomarker called troponin.  Troponin is elevated in the blood when there is damage to the heart muscle.  Previously the diagnostic pathway (EDACS-ADP) comprised one or two troponin measurements.  If the first measurement was very very low (no heart muscle damage) AND the electrocardiogram was normal AND the risk score was low the patient may be reassured they are not having a heart attack and go home (unless the physician thinks otherwise of course).  For the others there needs to be a second troponin measurement two hours later before a decision can be made to send home or admit to hospital.

What we were able to do in March last year was to identify a second group of patients whom physicians could confidentially call low-risk and send home after a single troponin measurement in the ED (ultimately it was decided that they were to have a second troponin the next day at a community laboratory).

It is one thing to analyse data and identify possible clinical improvement, it is quite another to actually make the change.  What was extraordinary in this case is that after we identified the possibility of a change the clinical, laboratory, managerial and administrative staff were able to implement the change in a matter of a few weeks so that on the 6th of May 2020 the new pathway went live with immediate effect (Figure 1).  Far fewer patients needed to have a second blood test in the ED, and so on average these chest pain patients were spending 30 minutes less each in the ED.  Additionally, there was a reduction in patients admitted to Cardiology who were ultimately diagnosed, not with a heart attack, but merely “Unspecified chest pain.”  In our publication of our experience in implementing this “COVID pathway” we identified a very large group of CDHB and University of Otago staff who were involved or whose earlier work made this transition possible.  For this work we were honoured to be recognised as both the Asia Pacific and one of three Top Global award winner by UNIVANTS of healthcare excellence (, ).


Figure 1: Fewer patients needed two troponin measurements two hours apart in the ED after the implementation of the new ADP

While we were fortunate that the influx of Covid patients did not come, such was the efficiency gains and the ability to reassure more patients early that they are not having a heart attack, the new pathway has remained in place.  While this is a tale of a silver lining to the COVID-19 pandemic it is also a tale of the tip of the iceberg. This tale was possible because of 13 years of previous work.  It began when Dr Than decided there needed to be something done about the 93% hospital admission rate for chest pain patients despite only 10-15% having a heart attack.  Several rounds of research in collaboration with University of Otago’s Christchurch Heart Institute including two randomised controlled trials and development of the risk score called EDACS all meant that when a very rapid change was needed, we had the data, and we had the people in place who trusted each other to work together to make that change happen.  The extraordinary result is that now, despite a large increase in population, the numbers of patients being admitted with the ultimate diagnosis of “unspecified chest pain” is now what it was in the 1990s (Figure 2).

Figure 2: Since the implementation of the first ADP Christchurch hospital has managed to reduce the numbers of those hospitalised for chest pain but without ultimately being diagnosed with a heart attack back to levels not seen since the 1990s.