1. Continuous Medical Education
Hospital Serdang
07 April 2009
Which chest pain can be safely
discharged from the ED?
Dr. Rashidi Ahmad
MD(USM), MMed(USM), AM(Mal)
Department of Emergency Medicine
Health Campus USM, Kelantan
3. Prehospital care
ED care
Specialist care
The flow of patients via the emergency care system
4. Epidemiology of Chest pain in ED
Buntinx F, et al. Chest pain in general practice or in the hospital emergency
department: is it the same? Fam Pract 2001;18:586-9.
5. Facts and figures
In UK, ~ ½ million patients with CP attend
ED each year
20-30% medical admissions ~ 50% had
ACS
6% of discharged patients had
significant myocardial damage
BMJ Publishing Group Jul 20, 2002
6. Cont…
In US, 100 millions ED visits; 8% had CP
5 million admissions
30% CCU admission (AMI); only 50-60% had ACI
24% of AMI patients inappropriately discharged
from ED
20% of malpractice claims against EPs relate to the
management of ACS
Western Journal of Medicine 2000; 172:329-31
7. 30%
60%
H. Domanovits et al. / Resuscitation 55 (2002) 9 /16
8. What are the Characteristics of
Misdiagnosed AMI Patients?
Misdiagnosed AMI is more likely to
occur among:
~ younger patients
~ atypical symptoms
~ less experienced physicians
~ fewer screening ECGs ordered
Murata, West J Med 1993; 159 (10): 61-68 Review
9. What are the Characteristics of
Misdiagnosed AMI Patients?
Retrospective study
10,689 patients evaluated ACS
Independent predictors of unrecognized cardiac
ischemia
- Women < 55 yrs (OR, 6.7)
- Non-white-race (OR, 2.2)
- Chief complaint of SOB (OR, 2.7)
- Normal ECG (OR, 3.3)
Pope et al. Missed diagnoses of cardiac ischaemia at the ED.NEJM 2000; 342:1163-70
10. The failure to diagnose
ACS is routinely listed
among the top five reasons for a
malpractice suite.
Reigelman R, Minimizing medical mistakes :
The Art of Medical Decision Making
11. Diagnostic challenges
Lack of specificity and sensitivity of the
historical data, the physical findings, and the
laboratory tests currently available.
Wagner JM, et al. JAMA 1996;276:1589-94
The American Journal of Emergency Medicine
Volume 23, Issue 4 , July 2005, Pages 483-487
12. Accuracy of history/PE
AMI ACS
Odds ratio (CI) Odds ratio (CI)
Chest pain radiation
Left arm 1.5 (0.6-4.0) 1.7 (0.9-3.1)
Right arm 3.2 (0.4-27.4) 2.5 (0.5-11.9)
Both left and right arm 7.7 (2.7-21.9) 6.0 (2.8-12.8)
Nausea or vomiting 1.8 (0.9-3.6) 1.0 (0.6-1.7)
Diaphoresis 1.4 (0.7-2.9) 1.2 (0.8-1.9)
Exertional pain 3.1 (1.5-6.4) 2.5 (1.5-4.2)
Burning/indigestion pain 4.0 (0.8-20.1) 1.5 (0.5-4.5)
Crushing/squeezing pain 2.1 (0.4-10.9) 0.9 (0.4-2.9)
Relief with nitroglycerin 0.9 (0.1-6.5) 2.0 (0.6-4.9)
Pleuritic pain 0.5 (0.1-2.5) 0.5 (0.2-1.3)
Tender chest wall 0.2 (0.1-1.0) 0.6 (0.3-1.2)
Sharp /stabbing pain 0.5 (0.1-2.8) 0.8 (0.3-2.1)
Goodacre S, et al. How useful are clinical features in the diagnosis of acute,
undifferentiated chest pain? Acad Emerg Med 2002 Mar;9(3):203-208.
13. How do traditional coronary risk factors
predict ACS in acute CP?
These risk factors identified in longitudinal
studies to predict development of CAD over
decades- not the likelihood of ACS in acute CP
At least 2 studies have confirmed that the
absence of risk factors does not exclude ACI
as an etiology for patient’s CP
Jayes et al. J Clin Epidemol 1992 ; 45 (6); Singh et al. Acad Emerg Med 2002 ;9;398-402
14. Electrocardiogram
~ 50% with a proven AMI have positive initial
ECG indicating the disorder
Up to 76% of ACS – normal an initial ECG, non
specific, or unchanged from previous ECG
Around 5% of CP patients with normal ECG who
were discharged from the ED were ultimately
found to have ACS
Mc Carthy B, Wong J. Detecting acute ischaemia in ED.
J Gen Int Med 1990; 5: 381-8
15. Relation between time &
ECG changes
Time Indication of infarct in
ECG
1st to 3 hours 40%
4th to 6th hour 50%
7th to 9th hour 90%
10th to 12th hour Up to 100%
ECG is a fairly specific but relatively insensitive test
for diagnosis of myocardial ischemia
16. Cardiac markers
Hours since
infarct... 0–4 4–8 8–12 12–24 24–48 48–72 >72
Patients (n) 34 26 41 76 76 69 67
Myoglobin (%) 55.8 92.3 85.4 75.0 43.4 20.3 14.0
95% CI 38.1–72.4 73.4–98.7 70.1–93.9 63.5–83.9 32.3–55.2 11.0–32.0 6.7–25.0
CKMB mass (%) 44.1 96.2 97.6 97.4 93.4 71.0 22.8
95% CI 27.6–61.9 78.4–99.8 85.6–99.9 90.0–99.5 84.7–97.6 58.7–81.0 13.2–34.8
Troponin-I (%) 35.3 80.7 92.7 97.4 96.1 97.1 93.0
95% CI 20.3–53.4 60.0–92.7 79.0–98.1 90.0–99.5 88.1–99.0 89.0–99.5 82.2–97.4
Combined (%) 61.8 96.2 97.6 97.4 98.7 98.6 94.7
95% CI 43.6–77.3 78.4–99.8 85.6–99.9 90.0–99.5 91.9–99.9 91.1–99.9 84.4–98.4
Serum markers for myocardial necrosis detect,
at best, 66% of J Med 1999; with AMI on arrivals
A. Chiu et al. Q patients 92: 711-718
Western Journal of Medicine 2000; 172:329-31
17. Prediction rule: TIMI Risk Score
Age > 65
3 or more Traditional Risk Factors (HTN, DM, Hyperchol,
FH, Smoking)
Known coronary stenosis of 50% or greater
ST-segment deviation on ECG
2 or more anginal events in past 24 hours
ASA use during past week
Elevated Cardiac Enzymes
3 or more of seven variables predicts increased risk of death or MI
(JAMA 2000; 284, p. 835)
18.
19. TIMI Rate of death, MI, revascularization
Score at 30 days
0 2.1 % (1.4-2.8)
1 5% (3.8-6.2)
2 10% (7.8-12.4)
Acad Emerg Med 2006;13(1):13
TIMI Rate of death, MI, revascularization
Score at 30 days
0 1.7 % (0.42-2.95) in this study,
age>65 fell out.
1 8.2% (5.27-11.04)
2 8.6% (5.02-12.08)
Ann Emerg Med 2006;48:252
20. Which chest pain can be safely
discharged from the ED?
It is not an easy answer!!
Over admission – not cost effectiveness
Inappropriate discharge – misdiagnosis/
mortality, law suit
ED workout – overcrowding/over burden
The traditional approach to CP is both
time-consuming and expensive
21. ED past and present
In the past: no true urgency in making a
rapid or definitive diagnosis of myocardial
ischemia
Recent ED: rapid diagnosis of ACS in ED is
vital (new medications, thrombolytic
therapy, emergency revascularization)
22. Diagnostic strategy in ED
Rule out AMI in appropriate patients
Rule out USA in appropriate patients
Rule out clinically significant CAD in
appropriate patients
Identify non-cardiac etiology of symptoms
in appropriate patients
24. Can we safely discharge young
patients with CP?
1023 patients
If a patient was between 24 and 39 years old,
had no known cardiac history, either no
classic cardiac risk factors or a normal ECG,
and initially normal cardiac marker studies,
the risk of ACS is only 0.14%.
No 30-day adverse cardiovascular events in
these patients.
Marsan RJ et al. Evaluation of a clinical decision rule for young adult
patients with CP. Acad Emerg Med 2005; 12: 26-31.
25.
26.
27.
28. Christenson J, Innes G, McKnight D, et al: A clinical prediction rule for early
discharge of patients with chest pain. Ann Emerg Med. 2006;47:1-10.
2006;47:1-
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39. Echocardiography
ACI a/w regional myocardial wall motion
abnormalities
Caveat: high false negative in ED
Highly technical, difficult to interpret
AMI: sen – 93%; spec – 66%
USA: sen – 70%; spec – 87%
Loandis et al. Ann Emerg Med 2001;37:478-94
40. Stress test
Explored the issue of appropriate discharge after ED
evaluation in an OU for outpatient risk stratification via EST
340 patients; 2 patients: fatal out-of-hospital cardiac events
27 subsequent chest pain visits to ED
Suggestions: a negative ED evaluation (serial ECG &
biomarkers) can identify patients at very low risk of short-
term cardiac events and appropriately selected patients can
be safely discharged for subsequent outpatient testing
Lai C, Noeller TP, Schmidt K, King P, Emerman CL: Short-term risk after
initial observation for chest pain. J Emerg Med. 2003;25:357-62
41. Cont..
Chan et al evaluated patients admitted to monitored
telemetry beds who received inpatient vs outpatient
vs no stress testing and found no difference in 30-
day outcome measures.
Smith et al examined the incidence of AMI in patients
with a documented negative stress test within the
previous 3 years and found that 4.8% of them were
diagnosed with AMI.
This implies that a recent negative stress test does
not conclusively rule out AMI when a patient has a
new episode of symptoms.
Chan GW et al. Am J Emerg Med 2003;21:282 - 7.
Smith SW et al. Acad Emerg Med 2005;12:51
42. Stress Echocardiography
Low-risk patients with a negative
stress echo have <1% rate for AMI and
cardiac death in the subsequent year
Marwick et al. J Am Coll Cardiol 1997;30(1):83-90
43. Use of 64-Section CT in Low-to-Moderate Risk
ED Patients Suspected of Having ACS
Coronary CT angiography was performed in 201
consecutive low-to-moderate risk ACS patients.
A triple rule-out protocol was used to evaluate for
coronary disease, pulmonary embolism, aortic
dissection, and other thoracic disease.
Subjects underwent a 30-day follow-up.
Takakuwa and Halpern. Radiology 2008: Vol 248: No, 2:438-46
45. A disease process other than coronary
atherosclerosis that explained the
presenting symptoms was diagnosed in 22
(11%) of 197 patients.
Clinically important non-coronary
diagnoses that did not explain patient
symptoms were identified in 27 (14%) of
197 additional patients.
46.
47. With respect to coronary artery disease:
- 10 patients severe disease (70% stenosis)
- 12 had moderate disease (50%– 70% stenosis)
- 46 had mild disease (up to 50% stenosis)
- 129 had no disease.
At 30-day follow-up, the negative predictive
value of coronary CT angiography with no
more than mild disease was 99.4%.
There were no adverse outcomes at 30 days.
Takakuwa and Halpern. Radiology 2008: Vol 248: No, 2:438-46
