By John Pickering 15/11/2017


Hundreds of nurses, Emergency Department doctors, Cardiologists and other specialists, laboratory staff, administrators and managers from every hospital in New Zealand with an emergency department have come together to implement new, effective, and safe pathways for patients who think they may be having a heart attack.

Today, Dr Martin Than (CDHB, Emergency Department) presented to the American Heart Association results of our research into the national implementation of clinical pathways that incorporate an accelerated diagnostic protocol (ADP) for patients with possible heart attacks.  Simultaneously, a paper detailing that research is appearing in the academic journal Circulation.

The headlines, are that in the 7 hospitals we monitored (representing about 1/3rd of all ED admissions in NZ a year), there was a more than two-fold increase in the numbers of patients who were safely discharged from the ED within 6 hours of arrival and told “It’s OK, you are not having a heart attack”.

 

Improving Care processes for patients with a possible heart attack.

 

Why is this important?

About 65,000 of the 1 million presentations to EDs each year in New Zealand are for patients whom the attending doctors think may be having a heart attack.  However, only 10-15% of those 65,000 are actually having a heart attack.  The traditional approach to assessment is long, drawn out, involves many resources, and means thousands of people are admitted into a hospital ward even thought it turns out they are not having a heart attack.  Of course, this means that they and their families have a very uncomfortable 24 hours or so wondering what is going on.  So, any method that safely helps to reassure and return home early some of those patients is a good thing.

What is a clinical pathway?

A clinical pathway is a written document based on best practice guidelines that is used by physicians to manage the course of care and treatment of patients with a particular condition or possible condition.  It is intended to standardise and set out the time frame for investigation and treatment within a particular health care setting – so it must take into account the resources available for a particular hospital.   For example, each hospital must document how a patient is assessed and if, for example, they are assessed within the ED as having a high-risk of a heart attack, where they must go.  In a large metropolitan hospital, this may mean simply passing them into the care of the cardiology department.  In a smaller setting like Taupo, where there is  no cardiology department, it may mean documenting when and how they are transported to Rotorua or Waikato hospital.

What is an accelerated diagnostic protocol?

An accelerated diagnostic protocol (ADP) is a component of the clinical pathway that enables the ED doctors to more rapidly and consistently make decisions about where to send the patient.  In all cases in New Zealand the ADPs for evaluating suspected heart attacks have 3 main components: (i) an immediate measurement of the electrical activity of the heart (an ECG), (ii) an immediate blood sample to look for the concentration of a marker of heart muscle damage called troponin, and a second sample 2 or 3 hours later, and (iii) a risk score based on demographics, prior history or heart conditions, smoking etc., and the nature of the pain (ie where it hurts and does it hurt when someone pushes on the chest, or when the patient takes deep breaths etc).   Importantly, these components enable a more rapid assessment of patients than traditionally and, in-particularly, enable patients to be rapidly risk stratified into low-risk, intermediate risk, and high-risk groups.  Usually the low-risk patients can be sent home.

What was done?

The Ministry of Health asked every ED to put in place a pathway.  Over an ~18 month period, a series of meetings were held at each hospital which were led by Dr Than, the clinical lead physician for the project.  Critically, at each meeting there were multiple members of the ED (doctors and nurses), cardiology, general wards, laboratory staff, and hospital administrators.  The evidence for different ADPs was presented.  Each hospital had to assess this evidence themselves and decide on the particularly ADP they would use.  Potential barriers to implementation and possible solutions were discussed.  Critically, champions for different aspects of the pathway implementation process were identified in each hospital.  These people led the process internally.

Oversight of the implementation was an ad hoc advisory board put together by the Ministry of Health and with MoH officials, Dr Than, Cardiologists, and myself.

The Improving Care processes for patients with suspected Acute Coronary Syndrome (ICare-ACS) study was a Health Research Council sponsored study with co-sponsorship of staff time by participating hospitals.  Its goal was to measure any changes in each hospital to the proportions of patients who were being discharged home from ED early and to check whether they were being discharged safely (ie to check that there were not people with heart attacks were being sent home).  Dr Than and I co-led this project, but there were many involved who not only set up the pathways in each of the 7 participating study hospitals, but who also helped with attaining the data for me to crunch.

What were the study results?

In the pre-clinical pathway implementation phase (6 months for each hospital) there were 11,529 patients assessed for possible heart attack. Overall, 8.3% of them were sent home within 6 hours of arrival (we used 6 hours because this is a national target for having patients leave the ED).  The proportions of patients sent home varied considerably between hospitals – from 2.7% to 37.7%.  Of those sent home early, a very small proportion (0.52%) had what we call a major adverse event (eg a heart attack, a cardiac arrest, or death for any reason) within 30 days.  This is actually a very good number (it is practically impossible to be 0%).

We monitored each hospital for at least 5 months after pathway implementation and a median of 10.6 months.  Of the 19,803 patients, 18.4% were sent home within 6 hours of arrival.  ie the pathway more than doubled the number of patients who were sent home early.  Importantly, all 7 of the hospitals sent more patients home earlier.  The actual percentages sent home in each hospital still varied, showing there are more further improvements to be made in some hospital than others.  Very importantly, the rate of major adverse events in those sent home remained very low (0.44%).  Indeed, when we looked in detail at the few adverse events, in most cases there was a deviation from the local clinical pathway.  This suggests that some ongoing education and “embedding in” of the pathways may improve safety even more.

The study also showed that amongst all patients without a heart attack the implementation of the pathway reduced the median length of stay in hospital by nearly 3 hours.  Using crude numbers for the cost of an acute event in a hospital I estimate that this is a saving to the health system of $9.5Million per year.  These types are calculations are difficult and full of assumptions, nevertheless, I can be confident that the true savings are in the millions (pst… Government… I wouldn’t mind a fraction of this saving to carry on research please).

How did this come about?

This study and the pathway implementation is the result of a decade long series of studies in Christchurch hospital and some international studies, particularly with colleagues in Brisbane.  These studies have involved ED staff, cardiologists, research nurses, University of Otago academics (particularly those in the Christchurch Heart Institute) and many others.  They began with an international onbservational study which measured troponin concentrations at earlier than normal time points to see whether they gave information that would enable earlier discharge of some patients.  This was followed by the world’s first randomised trial of an ADP verse standard (then) practice.  That showed that the ADP resulted in more patients being safely sent home.  It was immediately adopted as standard practice in Christchurch.  The ADP was refined with a more “fit for purpose” risk assessment tool (called EDACS – developed locally and with collaboration of colleagues in Brisbane).  The EDACS protocol was then compared to the previous protocol (called ADAPT) in a second randomised trial.  It was at least as good with potential for discharging safely even more patients.  It is currently standard practice in Christchurch.

As a consequence of the Christchurch work, the Ministry of Health said, effectively,  ‘great, we want all of New Zealand to adopt a similar approach’, and the rest, as they say, is history.  Now, all EDs have a clinical pathway in place, all use an evidence based ADP – two use the ADAPT and all the rest use EDACS with one exception which uses a more ‘troponin centric’ approach (still evidence based) which I won’t go into here.  Meanwhile, all of Queensland has adopted the ADAPT approach and we know of many individual hospitals in Australia, Europe and Iran (yes) which have adopted EDACS.

Other help

As mentioned already, the Health Research Council and the Ministry of Health along with all those medical professionals were integral to getting to where we are today.  Also integral, were all those patients who in the randomised trials agreed to participate.  Medical research is build on the generosity of the patient volunteer.  Behind the scenes is our research manager, Alieke, who ensures doctors run on time.  Finally, I am very fortunate to be the recipient of a research fellowship that enables me to do what I do.  I thank my sponsors, the Emergency Care Foundation, Canterbury Medical Research Foundation, and Canterbury District Health Board.  Some of the earlier work has also been done in part with my University of Otago Christchurch hat on.  Thank you all.