Cardiology/original research
The Accuracy of an Out-of-Hospital 12-Lead ECG for the Detection of ST-Elevation Myocardial Infarction Immediately After Resuscitation

https://doi.org/10.1016/j.annemergmed.2008.06.469Get rights and content

Study objective

Severe myocardial ischemia is the leading cause of arrhythmic sudden cardiac death. It is unclear, however, in which percentage of patients sudden cardiac death is triggered by ST-elevation myocardial infarction (STEMI) and whether the diagnosis of STEMI can be reliably established immediately after resuscitation from out-of-hospital sudden cardiac death.

Methods

A 12-lead ECG was registered after return of spontaneous circulation after cardiac arrest. After hospital admission, further ECG, creatine kinase MB, and troponin measures; results of coronary angiograms; and autopsies were evaluated to confirm the definitive diagnosis of STEMI.

Results

Seventy-seven patients were included in our study (67% men, age 64 [14 to 93] years). STEMI was diagnosed in 44 patients. The diagnosis of myocardial infarction was confirmed in 84% of the 77 patients who survived to hospital admission. The sensitivity of the out-of-hospital ECG was 88% (95% confidence interval [CI] 74% to 96%), the specificity 69% (95% CI 51% to 83%), the positive predictive value 77% (95% CI 62% to 87%), and the negative predictive value 83% (95% CI 64% to 87%). The accuracy of the out-of-hospital ECG and that registered on admission was the same.

Conclusion

The diagnosis of STEMI can be established in the field immediately after return of spontaneous circulation in most patients. This may enable an early decision about reperfusion therapy, ie, immediate out-of-hospital thrombolysis or targeted transfer for percutaneous coronary intervention.

Introduction

It is estimated that about one third of all patients experiencing an acute myocardial infarction die out of hospital in the field.1, 2, 3 Often, the so-called sudden cardiac death is the first and only symptom of coronary heart disease. Substantial progress has been made in the treatment of acute myocardial infarction in recent years. Different reperfusion strategies, newly developed antiplatelet agents, antithrombins, and improved preventive therapies have reduced inhospital mortality of myocardial infarction. However, there has been almost no reduction of the out-of-hospital case-fatality rate.4, 5

The prognosis of out-of-hospital cardiac arrest is poor, with a survival rate of less than 10%.6 Epidemiologic studies on the cause of arrest in patients with sudden cardiac death are difficult because autopsy rates are low in most countries and nearly zero in some countries such as Germany. Ventricular fibrillation, the most common arrhythmia underlying sudden cardiac death in adults, is triggered by cardiac ischemia.7 Correspondingly, in most patients, sudden cardiac death is caused by severe coronary heart disease.8, 9, 10 However, it is unclear in which percentage of patients sudden cardiac death is actually caused by acute ST-elevation myocardial infarction (STEMI).

The sensitivity of an out-of-hospital 12-lead ECG for the routine diagnosis of STEMI is about 70%, with an approximately 90% specificity in patients.11, 12, 13, 14, 15, 16, 17, 18 Prolonged ischemia, medication, and electrical countershocks during resuscitation may induce ECG alterations of variable extent, which may reduce its diagnostic reliability.19, 20 ST elevation (or a presumably new left bundle-branch block in symptomatic patients) in 2 or more contiguous leads in the ECG is by definition the principal diagnostic criterion of STEMI. According to the guidelines, reperfusion therapy in STEMI should be initiated as soon as possible after verification of the diagnosis.21, 22

To our knowledge, it has not yet been investigated whether it is possible to establish the diagnosis of STEMI with sufficient reliability on the basis of an ECG recorded immediately after the return of spontaneous circulation after out-of-hospital resuscitation from sudden death of assumed cardiac origin. We sought to determine the test characteristics of an out-of-hospital ECG registered immediately after return of spontaneous circulation.

Section snippets

Study Design

For the purpose of this prospective study, sudden cardiac death was defined as sudden and unexpected circulatory arrest of assumed cardiac origin, irrespective of the duration of preceding symptoms. Patients in whom resuscitation was attempted for clearly noncardiac reasons (eg, trauma, suicide, intoxication) were excluded from the study. If a noncardiac cause for resuscitation was recognized retrospectively, the patient was also excluded from the analysis.

Setting

Consecutive patients were included by

Results

From June 2002 to August 2004, we observed a total of 808 patients with an out-of-hospital cardiac arrest. Fifteen patients were primarily excluded from the study because of noncardiac causes of arrest (4 drowning, 4 intoxication, 7 trauma). One patient was retrospectively excluded because of diagnosis of intoxication. None of the patients had signs of myocardial infarction during the hospital course. In 362 patients, the resuscitation attempt was unsuccessful, and in 340 patients no

Limitations

Our study has several limitations. First, the registration of out-of-hospital ECG and interpretation was done by experienced physicians (two thirds internists and one third anesthesiologists). It remains unclear whether other providers may achieve similar or identical results. An alternative to ECG interpretation could be radio or telephone transmission to a hospital-based physician who may also decide on specific therapeutic procedures.

Second, a selection bias of patients cannot be excluded.

Discussion

In this study, we wanted to evaluate the significance of a standard 12-lead ECG registered immediately after successful out-of-hospital resuscitation in relation to the final diagnosis of acute ST-elevation myocardial infarction. This study was not designed or powered to differentiate between different patient groups prone to the underlying qualifying event for the out-of-hospital sudden cardiac death (eg, non ST-elevation myocardial infarction or STEMI). Previous studies have demonstrated a

References (33)

  • W. Lederer et al.

    Long-term survival and neurological outcome of patients who received recombinant tissue plasminogen activator during out-of-hospital cardiac arrest

    Resuscitation

    (2004)
  • E.H. Bradley et al.

    Door-to-drug and door-to-balloon times: where can we improve?time to reperfusion therapy in patients with ST-segment elevation myocardial infarction (STEMI)

    Am Heart J

    (2006)
  • D.S. Pinto et al.

    Door-to-balloon delays with percutaneous coronary intervention in ST-elevation myocardial infarction

    Am Heart J

    (2006)
  • B. Kuch et al.

    What is the real hospital mortality from acute myocardial infarction?epidemiological vs clinical view

    Eur Heart J

    (2002)
  • H. Lowel et al.

    [Temporal trends in myocardial infarct morbidity, mortality and 28-day fatalities and medical management. Results of the Augsburg Myocardial Infarct Register 1985 to 1992]

    Z Kardiol

    (1995)
  • L. Chambless et al.

    Population versus clinical view of case fatality from acute coronary heart disease: results from the WHO MONICA Project 1985-1990Multinational MONItoring of Trends and Determinants in CArdiovascular Disease

    Circulation

    (1997)

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    Supervising editor: Judd E. Hollander, MD

    Author contributions: DM, JB, and H-RA participated in the design of the study. DM, LS, and H-RA participated in patient recruitment. DM, LS, and JB conducted patient follow-up. DM, LS, and H-RA participated in preparation of the manuscript. DM takes responsibility for the paper as a whole.

    Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article that might create any potential conflict of interest. The authors have stated that no such relationships exist. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement.

    Publication dates: Available online August 22, 2008.

    Reprints not available from the authors.

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    Copyright © 2008 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.