Every year there are 6 million visits to the Emergency Department (ED) for chest pain, and approximately 2 million hospital admissions each year.1 This is approximately about 10% of ED visits and 25% of hospital admissions with 85% of these admissions receiving a diagnosis of a non-ischemic etiology to their chest pain (CP).2 This over triage has enormous economic implications for the US health care system estimated at $8 billion in annual costs.
Why do we do this?
Well, it could be that the single greatest contributor to financial losses in malpractice claims against emergency physicians comes from failure to accurately diagnose acute myocardial infarction (AMI).
So the question is
Are there specific aspects of the history that can increase or decrease the likelihood that a patient has acute coronary syndrome (ACS) and/or AMI?
There are 5 studies that were recommended by Dr. Amal Mattu, on his EMCast Podcast (July 2012) that evaluated the components of history that were more likely to correlate with ACS and/or AMI. Each will be reviewed below.
|Study||Number of Patients|
|Edwards et al., 2011||3306|
|Body et al., 2010||796|
|Swap et al., 2005||Literature Review|
|Goodacre et al., 2002||893|
|Panju et al. , 1998||Literature Review|
Relationship between pain severity and outcomes in patients presenting with potential acute coronary syndromes3
The main objective was to see if there was any correlation between severity of CP and the risk of AMI at presentation, or composite end points (death, revascularization, or acute myocardial infarction) at 30 days. Severe chest pain was defined as 9 – 10 on a pain scale of 0 to 10.
- Risk of AMI with Pain Score of 1 – 8 (82% of patients) = 3.0%
- Risk of AMI with Pain Score of 9 – 10 (18% of patients) = 3.9%
- Not statistically significant different
- Bottom Line: Severity of pain is not related to likelihood of AMI at presentation, or composite end points (death, revascularization, or AMI) at 30 days.
The objective was to assessing the value of individual symptoms for predicting a diagnosis of AMI or the occurrence of adverse events (death, AMI, revascularization via PCI or CABG) within 6 months.
- Strongest positive predictor of AMI
- Diaphoresis with CP
- Other positive predictors of AMI and adverse events
- Nausea and vomiting with CP
- CP with radiation to both shoulders > right shoulder > left shoulder
- Central chest pain
- Strongest negative predictor of AMI
- Pain located in the left anterior chest
- Other negative predictors of AMI and adverse events
- CP described as pain being the same as previous AMI
- Presence of CP at rest
- Bottom Line: Many “atypical” symptoms are more likely to render the diagnosis of ACS than traditional “typical” symptoms
Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes5
The authors wanted to identify the elements of a CP history that might be most helpful to the clinician in identifying ACS. They performed a literature search from 1970 to 2005.
- Bottom Line: No characteristics of chest pain alone, or in combination, identify a group of patients that can be safely discharge home without further diagnostic testing. Also beware the chest pain which radiates to the RIGHT shoulder (LR = 4.7).
How useful are clinical features in the diagnosis of acute, undifferentiated chest pain?6
In this prospective, observation cohort study of 893 patients, the authors assessed the performance of clinical features used in the diagnosis of CP, specifically in patients who were clinically stable and had a non-diagnostic EKG.
- Predictive of ACS/AMI:
- Exertional pain
- Pain radiating to both arms > right arm
- NOT predictive of ACS/AMI:
- Presence of chest wall tenderness
- Nausea or vomiting
- Bottom Line: Clinical features have a limited role in triage decision-making for ACS/AMI.
The rational clinical examination. Is this patient having a myocardial infarction?7
The final study is an oldie but a goodie. The authors aimed to identify clinical features that would increase or decrease the probability of an AMI, presenting with acute chest pain by reviewing the literature (1980-1991).
|Clinical Feature||Likelihood Ratio (LR+)|
|Chest pain that radiates to both arms||7.1|
|Chest pain that radiates to right shoulder||2.9|
|Features that INCREASE the probability of an AMI|
|Clinical Feature||Likelihood Ratio (LR-)|
|Pleuritic chest pain||0.2|
|Chest pain that is sharp/stabbing||0.3|
|Positional chest pain||0.3|
|Chest pain reproduced by palpation||0.3|
|Features that DECREASE the probability of an AMI|
Bottom Line: History alone can help, but can NOT rule out ACS/AMI!
Clinical factors that INCREASE likelihood of ACS/AMI
- CP radiating bilaterally > right > left
- Diaphoresis associated with CP
- N/V associated with CP
- Pain with exertion
Clinical factors that DECREASE likelihood of ACS/AMI
- Pleuritic pain
- Positional pain
- Sharp, stabbing pain
- Reproducible pain with palpation
These were all fantastic articles looking at aspects of the history in helping aide us in clinical decision making, but none of these historical elements alone or in combination can reliably help us rule in or rule out ACS or AMI. Just remember that there are some historical elements (with negative and positive likelihood ratios) that we need to ask our patients to assist in risk stratification in conjunction with an EKG and cardiac biomarkers.