EXPERTS have welcomed research showing that accelerated diagnostic protocols for patients presenting to emergency departments (EDs) with chest pain may reduce unnecessary testing, without compromising patient safety, and free up emergency department capacity.

In one study published in the MJA, researchers reported that three-quarters of patients presenting to EDs with chest pain could be rapidly assessed using risk stratification tools, early troponin testing and selective objective testing.

The Improved Assessment of Chest pain Trial (IMPACT) included 1366 patients who presented over 3 years to Royal Brisbane and Women’s Hospital with symptoms of suspected acute coronary syndrome (ACS).

Using the IMPACT protocol, patients were assessed as being at high risk (333 patients, 24.4%), intermediate risk (789 patients, 57.7%) and low risk (244 patients, 17.9%). High risk patients were treated according to the National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (CSANZ) guidelines, while low and intermediate risk patients underwent troponin testing (sensitive assay) at presentation and then 2 hours after presentation. Intermediate risk patients underwent objective testing after the second troponin test, and the low risk patients were discharged without objective testing.

The researchers found an overall 30-day ACS rate of 6.6%, none of which occurred in the low risk group. There were 14 ACS cases (1.8%) in intermediate risk patients.

In other research published in the same issue of the MJA, researchers evaluated the implementation of a 2-hour protocol outlined in the Accelerated Diagnostic protocol to Assess Patients with chest pain symptoms using contemporary Troponins as the only biomarker (ADAPT) study.

In the Accelerated Chest pain Risk Evaluation (ACRE) project, the ADAPT protocol was rolled out across 16 public hospitals in Queensland, and resulted in reduced hospital admissions (54.9%, down from 68.3%), and a shorter mean length of stay in the ED (256 minutes, compared with 292 minutes) in the 12 months after implementation.

Adoption of the protocol also released ED capacity estimated to be in the order of $2.3 million in reduced ED length of stay, and $11.2 million as a result of fewer hospital admissions.

Associate Professor Ian Scott, director of Internal Medicine and Clinical Epidemiology at Brisbane’s Princess Alexandra Hospital, said that these latest research findings added to evidence that low risk patients could be identified in the ED setting and safely discharged without further investigation.

“It’s pretty clear now that we can identify low risk patients and we can feel safe in discharging them, and we need to. There are increasing numbers of patients coming into EDs, and the increased capacity freed up by not admitting large numbers of low risk patients is important when you are dealing with hospitals that are always under bed stress,” he said.

Associate Professor Scott said that the recently released ACS clinical guidelines, of which he is a co-author, recommended the use of an accelerated diagnostic protocol, and there should be broader implementation of such protocols.

He said that an education campaign through various clinical networks could help increase clinician acceptance of these protocols, and financial incentives, such as those introduced by Queensland Health for quality improvement, may also be helpful in encouraging uptake.

Education of the public was also crucial, Professor Scott said. He said that often patients who presented to an ED with chest pain expected tests to be performed.

“We need to emphasise that our patients can be at risk of false positives by subjecting them to tests when they are at very low risk of ACS,” Professor Scott said.

Professor Mark Webster, CSANZ president, said that the IMPACT findings were reassuring.

“The findings are concordant with international data evaluating similar algorithms. The major limitation is the lack of power. When event rates are low – even in the intermediate risk group the rate was only 2% — large numbers are needed to be certain that there is discrimination between groups,” Professor Webster told MJA InSight.

“It would be reasonable to implement IMPACT, but continue prospective evaluation to evaluate larger numbers and confirm that the approach is safe. ACRE is also encouraging. It shows that implementation led by motivated senior clinicians would likely be effective in broadening uptake.”

Professor Louise Cullen, lead author of the IMPACT research, told MJA InSight in a podcast that the findings had significant implications for EDs, as well as hospitals and health services.

She said that the new low risk strategy meant that almost 20% of patients did not require further testing, resulting in an absolute reduction in testing. But more significantly, she said, was the shortened duration of testing for the almost 60% of patients assessed as being at intermediate risk.

“The median length of stay for our intermediate risk patients … was 7.5 hours, by comparison to our previous research, which showed that it was nearly a full 24 hours that those patients required to stay for testing,” said Professor Cullen, who is a senior staff specialist and emergency physician at the Royal Brisbane and Women’s Hospital.

Speaking in another MJA InSight podcast, lead author of the ACRE study, Professor William Parsonage said that their findings had exceeded expectations in showing reductions in either admissions or length of stay in all 16 hospitals studied.

“Given that the intervention is pretty simple – we weren’t using any new, expensive technology; we were just really using the same clinical methods and the same tests that we were using beforehand – it’s really just the cost of implementing the [accelerated diagnostic protocol] that would be offset against those gains,” said Professor Parsonage, who is senior staff cardiologist at the Royal Brisbane Women’s Hospital and clinical director of the Centre for Health Service Innovation at the Queensland University of Technology.

In an MJA editorial accompanying the two studies, cardiologist Dr Jonathan Christiansen also welcomed these two research projects. He pointed to the importance of keeping the patient at the centre of decisions about their health care.

“Combined with other improvements in applying chest pain pathways, shared decision making is vitally important for avoiding low value care and improving resource use.”


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6 thoughts on “Safe and faster way to triage chest pain

  1. healthsciencewriter says:

    Please stop using images of elderly males in agony. You perpetuate the impression that women are not at risk and have these acute symptoms.

  2. Sue Ieraci says:

    Thanks, Will. The other issue here is the definition of the term “risk” – the literature, and its application in clinical practice, confuses risk of having the disease with risk of a significant adverse event.

    If only 1.8% of “intermediate risk” patients had ACS, that means that 98.2% of “intermediate risk” patients didn’t have ACS. That’s much better than most exclusion criteria. What, then, was this group of intermediate risk FOR, and why are we using such poor risk classification tools?

  3. Will Parsonage says:

    Sue I think your comments are fair. What we have tried to do in our research is to provide robust, evidence based frameworks that can help improve the value of care in this large group. EDs are large, busy places with rapid turnover of staff so in that context we think that simple but safe pathways are of value in this context. ImpACT is the next step but ACRE shows what can be achieved with a simple intervention for a large problem when implemented on a wide scale. Thanks for your interest and positive comments.

  4. Sue Ieraci says:

    We are getting to the point where over-diagnosis of chest pain can cause as much harm as under-diagnosis. One of the major issues is the application of the pathway to a low-prevalance population (young helathy people with chest pain of any duration), which results in excess false positives. At the other end of the scale, use of troponins in assessing the frail elderly leads to a cascade of “artery opening” interventions in patients who are more likely to have diffuse coronary disease, with demand/supply limitations, rather than aa acute single vessel occlusion.

    Interventional Cardiology carries risks as well as cost. We know, from good quality data, that stenting in teh absence of AMI does not improve outcomes. Just the creation of cardiac anxiety and limitation of lifestyle can be an adverse effect of putting a young healthy person through an ACS work-up. In our EDs, risk-aversion has made us push almost anyone presenting with chest pain – even teenagers – through a pathway to “rule out ACS” rather than an attempt to actually diagnose or reassure. We may forget to ask ourselves, realistically, do I really think this is angina?

    I admire Louise Cullen and colleagues for producing this important, real-world analysis of what we are doing. Their work has shown that very few of the tested patients were actually found to have had an ischaemic event (“ACS”) – much less death.

    Prof Scott says: “said that these latest research findings added to evidence that low risk patients could be identified in the ED setting and safely discharged without further investigation.” This has always been the case. Young healthy people who look well, have another explanation for their pain plus or minus a normal ECG have always been able to be safely discharged from ED, the same as low risk patients for any condition – be it sepsis, or bowel obstruction.

    It’s great that we’ve reduced the time spent looking for ACS in people who are unlikely to have it. The next step might be to target our time and resources to those who are likely to benefit from the work-up.

  5. Will Parsonage says:

    CC – Please read the paper – the 1.8% event rate was in the intermediate (not low) risk group and the events (largely UAP) were detected by the investigation strategy – arguably detected earlier than they would have been using more traditional guidelines.

  6. CC says:

    it depends on what you mean by “low risk”. sometimes there are differences of opinion.
    sometimes the intern tells me one story, but the patient tells me a different story.
    it isn’t always straightforward…
    figures such as 1.8% might not sound like much but we are dealing with many thousands of chest pain patients, and sooner or later someone draws the short straw.

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