Annals of Emergency Medicine
Volume 44, Issue 6 , Pages 575-576, December 2004

Chest pain in the emergency department: In search of the Holy Grail

From the Clinical Research Unit, Kaiser Permanente Colorado, Denver, CO (Magid); the Department of Preventive Medicine and Biometrics (Magid), the Division of Emergency Medicine (Magid), and the Division of Cardiology (Rumsfeld, Masoudi), University of Colorado Health Sciences Center, Denver, CO; and the Denver VA Medical Center (Rumsfeld) and Denver Health Medical Center (Masoudi), Denver, CO

published online 01 October 2004.

See related article, p. 565.

Article Outline

 

The current approach to patients presenting to the emergency department (ED) with possible acute coronary syndrome lacks the discrimination to optimize both the safety and efficiency of clinical care. Prior studies suggest that 2% of ED patients who present with acute myocardial infarction and another 2% who present with unstable angina are inadvertently discharged home after their ED evaluation.1 Conversely, more than half of patients admitted from the ED for further evaluation of possible acute coronary syndrome are ultimately diagnosed with a noncardiac condition.2., 3.

Because the intensity of the ED evaluation of patients presenting with chest pain is proportional to the clinician's estimate of patient risk, it is particularly important to understand the clinical course of patients deemed to have a low likelihood of acute coronary syndrome. In the study by Miller et al4 in this issue of Annals, the investigators asked emergency physicians to assess the likelihood that a given patient was experiencing an acute coronary syndrome after completing a history, physical examination, and review of the ECG.4 ED providers recorded their diagnostic impression as definite acute coronary syndrome, high-risk chest pain, low-risk chest pain, or noncardiac chest pain. The objective of the study was to determine the rate of adverse cardiac events in the cohort of patients classified as having “noncardiac” chest pain. Overall, 2.8% of these “noncardiac” chest pain patients experienced an adverse cardiac event in the 30 days after the initial ED evaluation. A prior history of coronary artery disease, a higher Acute Cardiac Ischemia–Time Insensitive Predictive Instrument score, and several risk factors for coronary artery disease were associated with an increased risk of subsequent cardiac events among these patients.

What are the primary implications of this study? First, it does not suggest that all ED chest pain patients require admission to the hospital. However, it reinforces the idea that patients with a history of and/or risk factors for coronary artery disease are at increased risk of acute coronary syndrome. This complements previous work by Goldman et al5., 6., 7. that identified clinical features associated with acute coronary syndrome (eg, chest pain associated with diaphoresis or chest pain similar to a prior acute coronary syndrome event). Taken together, these studies suggest that physicians should pursue a more extensive workup than a history, physical examination, and ECG in patients with typical angina, known coronary artery disease, or coronary risk factors.

Second, the finding that higher Acute Cardiac Ischemia–Time Insensitive Predictive Instrument scores are an independent risk factor for subsequent cardiac events underscores the importance of competency in ECG interpretation. This result is consistent with the study of Pope et al1 in which a significant number of patients mistakenly discharged from the ED with acute coronary syndrome had ischemic abnormalities on their ECG. This finding also supports the National Heart Attack Alert Program recommendation that the Acute Cardiac Ischemia–Time Insensitive Predictive Instrument be used in the initial evaluation of patients presenting with signs and symptoms of acute coronary syndrome.8

Several limitations of the study by Miller et al4 should be noted. It is not clear how the ED providers in this study made the determination that a patient had “noncardiac” chest pain. Formal criteria were not established, and the investigators did not report detailed history, physical examination, or ECG findings associated with the ED provider's classification. Furthermore, the proportion of patients undergoing cardiac biomarker testing was identical for those patients classified as “low risk” and those classified as “noncardiac,” suggesting that the ED providers had difficulty distinguishing these 2 groups. In fact, emergency physicians admitted 88% of the “noncardiac” chest pain patients who subsequently experienced an adverse cardiac event. This hospital admission rate is more than 3 times higher than for the general population of “noncardiac” chest pain patients, suggesting that the emergency physicians deliberately pursued a more extensive evaluation in this subset despite their clinical classification. Finally, it is possible that ED providers were more likely to perform cardiac biomarker testing and admit “noncardiac” chest pain patients with risk factors for coronary artery disease. Thus, we cannot exclude workup bias as a possible explanation for the increased rate of subsequent cardiac events in patients with coronary risk factors found in this study.

Ultimately, further studies are needed to better define the group of patients who are truly at very low risk for acute coronary syndrome for whom the history, physical examination, and ECG are sufficient. Only then will physicians be armed with the tools to optimize both the safety and efficiency of care for patients presenting to the ED with chest pain.

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References 

  1. Pope JH, Aufderheide TP, Ruthazer R, et al. Missed diagnoses of acute cardiac ischemia in the emergency department. N Engl J Med. 2000;342:1163–1170
  2. Selker HP, Griffith JL, D'Agostino RB. A tool for judging coronary care unit admission appropriateness, valid for both real-time and retrospective use. A time-insensitive predictive instrument (TIPI) for acute cardiac ischemia: a multicenter study. Med Care. 1991;29:610–627
  3. Roberts R, Kleiman NS. Earlier diagnosis and treatment of acute myocardial infarction necessitates the need for a “new diagnostic mind-set”. Circulation. 1994;89:872–881
  4. Miller CD, Lindsell CJ, Khandelwal S, et al. Is the initial diagnostic impression of “noncardiac chest pain” adequate to exclude cardiac disease?. Ann Emerg Med. 2004;44:565–574
  5. Goldman L, Weinberg M, Weisberg M, et al. A computer-derived protocol to aid in the diagnosis of emergency room patients with acute chest pain. N Engl J Med. 1982;307:588–596
  6. Goldman L, Cook EF, Brand DA, et al. A computer protocol to predict myocardial infarction in emergency department patients with chest pain. N Engl J Med. 1988;318:797–803
  7. Goldman L, Cook EF, Johnson PA, et al. Prediction of the need of the intensive care in patients who come to emergency departments with acute chest pain. N Engl J Med. 1996;334:1498–1504
  8. Selker HP, Zalenski RJ. An evaluation of technologies for detecting acute cardiac ischemia in the emergency department: a report of the NIH national heart attack alert program. Ann Emerg Med. 1997;29:13–87

 The authors report this study did not receive any outside funding or support.

 Reprints not available from the authors.

PII: S0196-0644(04)00571-2

doi:10.1016/j.annemergmed.2004.06.001

Refers to article:

  • Is the initial diagnostic impression of “noncardiac chest pain” adequate to exclude cardiac disease? , 19 August 2004

    Chadwick D. Miller, Christopher J. Lindsell, Sorabh Khandelwal, Abhinav Chandra, Charles V. Pollack, Brian R. Tiffany, Judd E. Hollander, W. Brian Gibler, James W. Hoekstra
    Annals of Emergency Medicine December 2004 (Vol. 44, Issue 6, Pages 565-574)

Annals of Emergency Medicine
Volume 44, Issue 6 , Pages 575-576, December 2004

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