Anne-Maree Kelly

Joseph Epstein Centre for Emergency Medicine

Research @ Western Health

CHEST PAIN ASSESSMENT:

IS CLINICIAN GESTALT UNDER-VALUED?

OR…

OF HORSES, ZEBRAS AND UNICORNS

PERMISSION TO USE

Professor Kelly gives permission for this material to be used for

educational purposes (personal or group) on the basis that:

•The original source is acknowledged

•No liability is accepted by her for the currency or setting relevance of the

content

CONFLICTS OF INTEREST

I am a recently ‘retired’ member of the core writing group for the National Heart

Foundation/ CSANZ Guidelines for the Management of Acute Coronary

Syndromes (2006-2014) .

The opinions expressed are my personal views and do not reflect the opinions of

NHF/CSANZ.

I am a member of advisory boards for AstraZeneca, Novartis and MSD with

respect to cardiac therapeutics.

THE SHAPE (AND SIZE) OF THE PROBLEM

• Patients with chest pain are very common in Australasian emergency departments.

• In Victoria, of 1.5 million ED attendances annually, an estimated 37,500 patients undergo an ACS rule out process.

• The ‘rule in’ rate for ACS is ~15-20%, depending on how you count.

• ACS rule out usually requires a prolonged period of observation and testing.

• The vast majority of patients undergo an assessment process in ED and are discharged.

THE OTHER SIDE OF THE PROBLEM

• Claims for missed or delayed diagnosis of ACS are among the most

common claims settled by insurers.

• Missed ACS has serious consequences for patients/ families.

• Higher rate of death and serious complications.

RATE OF MISSED MYOCARDIAL INFARCTION

McCarthy et al. 1993.

1.9% (1.2-2.9%)

Schull et al. 2006.

2.1% (1.9-2.3%)

Rate varied across ED from

0% to 29%.

Lower ‘miss’ rates:•High volume ED

•Emergency physician

supervision

Wilson et al 2014.

0.52% (0-3.45%)

Lower ‘miss’ rates:

•Individual factors• More frequent exposure to

higher chest pain acuity

• ‘Board certified’ staff

•Setting factors• Larger hospital

• Academic centre

RATE OF MISSED MYOCARDIAL INFARCTION

McCarthy et al. 1993

1.9% (1.2-2.9%)

Schull et al. 2006

2.1% (1.9-2.3%)

Rate varies across ED

from 0% to 29%.

Lower ‘miss’ rates:

•High volume ED

•Consultant supervision

Wilson et al 2014.

0.52% (0-3.45%)

Lower ‘miss’ rates:

•Individual• More frequent exposure to

higher chest pain acuity

• Board certified’ staff

•Setting• Larger hospital

• Academic centre

Increasing biomarker sensitivity

RISK TOLERANCE FOR MISSED ACS

• Likely to depend on your point of view:

• Patients & families

• Emergency physicians

• Cardiologists

• Insurers / medico-legal system

• Healthcare funders

WHAT DO PATIENTS THINK?

• No Australasian data

• Pilot study from the US (Brown et al; 2010)

• 68 patients (31 known heart disease)

• Median decision threshold was 6.5% (IQR 0.5-22.9%)

• Most often reported value was 0.5%

• 44% of patients had decision threshold at 1% or less

If you knew that there was a risk

of something bad happening to

you related to your heart (heart

attack, urgent surgery, death) at

what probability of an event

would you want to be admitted to

the hospital rather than

discharged home?’

RISK TOLERANCE MISSED ACS

• The limited available data suggests a lack of consensus among

emergency physicians about what level of risk is ‘acceptable’.

• There are no published data for:

• Cardiologists

• Insurers / medico-legal system

• Healthcare funders

WHAT DOES IT ALL MEAN?

• There is variation between emergency physicians and

between patients about the level of acceptable risk.

• Both tend to favour levels ≤1%

• Is this realistic or achievable?

• Is this cost-effective?

THE CHEST PAIN ASSESSMENT PROCESS

• ECG

• Clinical assessment• History• Physical exam

• Biomarkers

• Other tests (selected cases)

• Further testing for CAD• Before or after discharge• Stress ECG, nuclear medicine studies, CTCA, etc.

THE CHEST PAIN ASSESSMENT PROCESS

• ECG

• Clinical assessment• History• Physical exam

• Biomarkers

• Other tests (selected cases)

• Further testing • Before or after discharge• Stress ECG, nuclear medicine studies, CTCA, etc.

Identify STEMI

Physician gestalt

Formulation of differential diagnosis

and investigation/management plan

Gestalt/ɡəˈʃtælt/

A perceptual pattern possessing qualities as a whole

that cannot be described merely as a sum of its parts

IT’S ABOUT ….

• Picking when something does not quite add up

• Knowing when to ask/ search a bit more

• Picking the rare from the common

• Appropriately weighting the throw away comment

• A feel for when an apparently well-looking patient is at

serious risk

• Accurately identifying low risk patients

Non-serious, non-

ACS causes

Myocardial infarction

Pulmonary embolism

Aortic dissection

Spontaneous intramural

oesophageal haematoma

OF HORSES, ZEBRAS AND UNICORNS

SO, WHAT GOOD IS PHYSICIAN GESTALT ?

• In chest pain assessment, physician gestalt has been increasing side-lined.

• Reasons include:• High prevalence of ‘atypical’ symptoms of ACS

• Drive to achieve lower and lower rates of missed ACS

• Documented variation in practice

• Medico-legal climate

• Patient flow pressures

WHAT GOOD IS PHYSICIAN GESTALT ?

• There is a move towards risk factors, biomarkers, risk stratification

scores, clinical decision aids & chest pain pathways.

• There focus on ACS rather than other serious diagnoses.

• BUT:

• Gestalt has been shown to have independent diagnostic value in

other conditions, e.g. DVT and PE.

WHAT GOOD IS PHYSICIAN GESTALT ?

• There is a move towards risk factors, biomarkers, risk stratification

scores, clinical decision aids & chest pain pathways.

• BUT:

• Gestalt has been shown to have independent diagnostic value in

other conditions, e.g. DVT and PE.

‘TRADITIONAL’ CARDIAC RISK FACTORS

• Traditional cardiac risk factors are associated with population risk of

coronary artery disease

• They are widely taught as part of the assessment chest pain patients in ED

• Cardiologists place a lot of store in them!

Jayes et al. 1992

• Question: Does the presence of cardiac risk factors increase the likelihood of ACS?

• No impact in women

• Diabetes and family history minimal impact in men (low OR)

THE FUTILITY OF CARDIAC RISK FACTORS

Han et al. 2007

• Question: Does the number of cardiac risk factors increase the likelihood of ACS?

• None vs ≥4 significant in age <40 (NLR 0.17 vs. PLR 7.39)

• Limited clinical value in age >40

Schrock et al. 2011

• Question: Does the presence of cardiac risk factors increase the likelihood of a positive stress test?

• AUC for diagnostic performance 0.59-0.62.

Jayes et al. 1992

• Question: Does the presence of cardiac risk factors increase the likelihood of ACS?

• No impact in women

• Diabetes and family history minimal impact in men (low OR)

THE EVIDENCE

Han et al. 2007

• Question: Does the number of cardiac risk factors increase the likelihood of ACS?

• None vs ≥4 significant in age <40 (NLR 0.17 vs. PLR 7.39)

• Limited clinical value in age >40

Schrock et al. 2011

• Question: Does the presence of cardiac risk factors increase the likelihood of a positive stress test?

• AUC for diagnostic performance 0.59-0.62.

Traditional cardiac risk factors have very limited usefulness at the

individual level in ED patients with chest pain

GESTALT - THE EVIDENCE

• i*trACS study

• Gestalt = ‘noncardiac chest pain’ after initial assessment and ECG

• Rate of MACE=2.8% (2.3-3.5%)

• 53% of these identified in ED by biomarkers

• 4 were identified with MI but discharged

• Adjusted ‘miss rate’ =36/2992 = 1.2% (0.9-1.7%)

Miller et al. 2004

GESTALT - THE EVIDENCE

• Multi-site prospective US study.

• Gestalt assessment before biomarker analysis.

• Of 293 patients with pre-test probability of ACS by gestalt ≤ 2%; 2 MACE

• Sensitivity: 96.1% (95% CI 86.5-99.5%).

• Sensitivity similar to computer-based attribution matching approach and ACI-TIPI.

• AUC for diagnostic performance = 0.78 (0.7-0.86).

Mitchell; 2006

GESTALT - THE EVIDENCE

• Investigated gestalt + ECG vs. gestalt

+ ECG + single troponin assay

Body; 2014

Sensitivity Specificity NPV

Gestalt + ECG* 95

(88-99)

32

(27-37)

97

(92-99)

Gestalt + ECG +

troponin

100

(96-100)

28

(24-100)

100

(97-100)

* Low risk defined as ‘definitely not’ and ‘probably not’ ACS

Physician gestalt was independently predictive of AMI (OR 2.4; 95% CI 1.6-3.6)

& MACE (OR 2; 95% CI 1.4-2.7).

GESTALT - THE EVIDENCE

• Compared HEART score and physician gestalt

• Note: The HEART score includes an element of physician gestalt

• Diagnostic performance (by AUC) similar:• 0.81 (0.76-0.86) for HEART score

• 0.79 (0.73-0.84) physician gestalt

Visser, 2014

GESTALT OR PREDICTION SCORES?

HEART

score

AUC

Visser 0.81

(0.76-0.86)

Six 0.83

(0.81-0.85)

GRACE

FFE

score

AUC

Kelly 0.74

(0.62-0.86)

GRACE RISK

score

AUC

Cullen 0.83

(0.79-0.86)

Lyon 0.80

(0.75-0.85)

NHF

score

AUC

Burkett 0.54

(0.45-0.63)

Cullen 0.75

(0.70-0.80)

TIMI

score

AUC

Burkett 0.71

(0.63-0.79)

Cullen 0.79

(0.74-0.83)

Lyon 0.76

(0.74-0.85)

Six 0.75

(0.72-0.77)

Gestalt AUC

Mitchell 0.78

(0.70-0.80)

Body 0.76

(0.70-0.82)

Visser 0.79

(0.73-0.84)

Clinical bottom line: • Not much difference between gestalt and prediction scores

• Both are unsuitable for use alone to identify low risk group for early discharge

WHAT ABOUT THE ‘GOOD’ STORY?

• Young-ish patient with rapidly progressive angina on exertion

• Discussion with Cardiology punctuated by the questions:

• What are his cardiac risk factors?

• What is the troponin?

• Often we have to fight to get the patient admitted for early

angiography.

• We are proved ‘right’ the vast majority of the time.

THE SEARCH FOR THE ‘MAGIC’ BIOMARKER

• Strong emphasis in cardiology research

• Highly focussed on ‘MI’ vs. ‘no MI’ with emphasis on early detection of MI

• Fail to consider the need to rule out other diagnostic possibilities

• Lack of specificity of biomarkers is problematic

• They are interested in rule in and we are interested in rule out

THE MEDICO-LEGAL WORLD

• Coronial case reviews

• The commonest cases I see are of missed aortic dissection:

• In almost all cases, patients presented with chest pain of some sort.

• In the majority, patients were managed according to chest pain (rule

out ACS) pathways.

• In the majority, there were important clues in the clinical information

that were either not elicited or incorrectly interpreted.

CORONER’S RECOMMENDATION

• Structured review of a series of cases in Victoria by Coroner Spanos has led

to the formal coronial recommendation to hospitals, ACEM and the

Department of Health that chest pain pathways include reminders to consider

other important serious diagnoses such as aortic dissection or pulmonary

embolism.

PROS & CONS OF CHEST PAIN PATHWAYS

B E N E F I T S

• Consistency

• Promotes evidence-based care

• Patient flow

• Standard documentation

• Can be multidisciplinary

• Tool for quality and research analysis

R I S K S

• Can get out of date

quickly

• Can promote cognitive

error

• Diagnostic momentum

• Premature closure, etc.

INCONSISTENCY OF GESTALT?

• There is evidence that the quality of physician gestalt is not consistent

• Between individuals

• Lower missed MI rates in ‘board certified’ & those assessing high risk chest pain regularly

• Between settings

• Lower missed MI rates in larger centres & in academic centres

HOW DO WE TEACH & REFINE GESTALT?

• Good gestalt requires high quality information gathering• This can be taught• Pressures of ED promote short-cuts in information gathering

• Gestalt also requires integration of data and appropriate clinical reasoning

• Not just history and exam• From all senses and what is ‘said’ and ‘not said’• Awareness of context• Balance of intuition and analysis

‘IT’S ALL ABOUT EXPERIENCE’

• The ‘old school’ approach has been that the development and

maintenance of ‘gut feeling’ or ‘gestalt’ is all about experience.

• The more experience you have, the better your gut feeling will be.

• Little attention to the quality of the experience and how it is

integrated into future practice.

IT’S ALL ABOUT EXPERIENCE

• The ‘old school’ approach has been that the development and

maintenance of ‘gut feeling’ or ‘gestalt’ is all about experience.

• The more experience you have, the better your gut feeling will be.

• Little attention to the quality of the experience and how it is

integrated into future practice.

Slow, inefficient, unstructured, open to bias & over-

weighting of selected experiences

Inappropriate

over-confidence

Inappropriately

defensive practice

Time alone does not deliver high quality clinical gestalt

TEACHING CLINICAL REASONING

• Should be thought of as a skill, not something ‘picked up as you go

along.’

• Taught in medical schools but teaching needs to continue throughout

training.

• Takes effort to structure into emergency department processes.

• New ACEM workplace-based assessments will hopefully foster

better teaching of clinical reasoning.

IMPORTANT COMPONENTS OF SKILL ACQUISITION

• Case-based learning & discussions (individual and group)

• Demonstration and de-construction of ‘expert’ clinical reasoning

• Observed clinical encounters with discussion of ‘what were you

thinking then’ & feedback

• Encouraging follow-up of cases to check ‘accuracy’

• Teaching reflective practice skills

• Teaching about cognitive error (and strategies to mitigate it)

REFINEMENT & MAINTENANCE OF GESTALT

• Reflective practice.

• Case-based discussions with peers (and trainees).

• Active (constructive) learning from adverse events/ error/ complaints.

• Case follow-up.

• Developing awareness of individual cognitive biases.

SUMMARY

• In current chest pain assessment processes there is a real risk of physician gestalt being undervalued.

• It is particularly important for evaluating and managing the risk of serious non-ACS conditions.

• In ACS, there is evidence that it can have similar accuracy to other risk stratification tools.

• When used in combination with ECG and a single troponin can accurately identify a very low risk group for ACS.

• BUT

• There is variation in the quality of gestalt –individual & setting factors.

• Teaching and maintaining high quality gestalt is challenging in ED setting.

CONCLUSION

• Gestalt should be re-valued in diagnostic

processes, including chest pain assessment.

• Active strategies to develop and refine gestalt

should be part of education and continuing

professional development programs.

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