The risk for acute coronary syndrome associated with atrial fibrillation among ED patients with chest pain syndromes

doi:10.1016/j.ajem.2006.09.015

The American Journal of Emergency Medicine

Volume 25, Issue 5, June 2007, Pages 523-528

https://doi.org/10.1016/j.ajem.2006.09.015 Get rights and content

Abstract

Objective

We sought to determine if atrial fibrillation is associated with an increased risk for an acute coronary syndrome (ACS) among emergency department (ED) patients with chest pain syndromes.

Methods

We performed a retrospective analysis of a prospectively collected database on ED patients with chest pain by selecting patients with atrial fibrillation and frequency-matched control subjects without atrial fibrillation. Measured outcomes were acute myocardial infarction (AMI), ACS, and unstable angina (UA). The relative risks of AMI, ACS, and UA associated with atrial fibrillation were calculated.

Results

One hundred forty patients with atrial fibrillation and 683 matched control subjects were identified. The rates of AMI for the atrial fibrillation and control groups were 11.4% and 10.8%, respectively; those of ACS were 27.9% and 26.7%, respectively; and those of UA were 16.4% and 15.8%, respectively. The relative risks of AMI and ACS did not increase in patients with atrial fibrillation: AMI, 1.05 (95% confidence interval [CI] = 0.63-1.75); ACS, 1.05 (95% CI = 0.78-1.40); and UA, 1.05 (95% CI = 0.6-1.7).

Conclusion

Among patients presenting to the ED with chest pain syndromes, atrial fibrillation is not associated with an increased risk for AMI, ACS, and UA.

Introduction

Atrial fibrillation is the most common cardiac dysrhythmia, accounting for more than 2.3 million cases in the United States [1]. One percent of all patients presenting to the emergency department (ED) have atrial fibrillation [2], and the risk for myocardial infarction among these patients is 5.5% [3]. New-onset atrial fibrillation is known to occur in the setting of an acute myocardial infarction (AMI) [4], [5], [6], [7]. In addition, atrial fibrillation is associated with increased in-hospital mortality in the setting of an acute coronary syndrome (ACS) [8], [9], [10]. Approximately 39% of patients with atrial fibrillation present with concurrent chest pain [3]. Among ED patients with atrial fibrillation, lack of chest pain has been associated with a lower risk for AMI, suggesting that lone atrial fibrillation in patients without traditional risk factors or a presentation otherwise suggestive of ACS may not require evaluation to rule out ACS [3], [11]. Many risk factors for ACS have been examined among the approximately 6 million patients who present with chest pain to EDs in the United States each year [12], [13], [14], [15], [16], [17], [18], [19]. However, it is not known if atrial fibrillation by itself is a risk factor for myocardial ischemia among patients presenting to the ED with chest pain suspected to be associated with ACS or simply a marker of previously identified risk factors among these patients.

We hypothesized that the presence of atrial fibrillation was not a risk factor for AMI or ACS among patients presenting to the ED with chest pain suspected to be associated with a potential ACS.

Section snippets

Study design

We performed a retrospective analysis of a prospectively collected cohort of ED patients with chest pain comparing matched cohorts of patients with and those without atrial fibrillation to determine whether the presence of atrial fibrillation upon ED arrival is associated with AMI, ACS, or unstable angina (UA). Frequency matching was used to select a control cohort with similar baseline characteristics and cardiac risk factors.

Setting

This study was conducted at the ED of an urban tertiary care center

Population characteristics

Five thousand five hundred fifty-seven eligible patients with chest pain and ECGs were included in the 2 databases. From this population, there were 4715 unique patients without atrial fibrillation and 140 unique patients with atrial fibrillation. Six hundred eighty-three unique patients without atrial fibrillation were selected via frequency matching as control subjects.

There was no significant difference between the groups on the matched baseline characteristics. The populations were similar

Discussion

Previous studies have reported a relatively low risk ranging from 2% to 5% for myocardial ischemia among ED patients with atrial fibrillation and established that the traditional predictors of ischemia hold true for this population, including typical chest pain and ST-segment deviation [3], [11]. These studies included patients with atrial fibrillation only, so they were unable to elucidate if the presence of atrial fibrillation was associated with additional risk for ACS among ED patients with

Limitations

We acknowledge several limitations of this study. This was a retrospective analysis of a prospectively collected database that used matching—it has the limitations inherent in this type of study. Selection bias was limited by screening all patients presenting to the ED with chest pain during the enrollment periods. All patients with atrial fibrillation were included, and random samplings of patients without atrial fibrillation from a matched stratum were selected to limit unknown confounders.

Conclusions

Atrial fibrillation is not associated with an increased risk for AMI or ACS among patients presenting to the ED with chest pain syndromes. Therefore, dispositions of decisions regarding ruling out acute ischemia among patients with chest pain syndromes should not be altered by the presence of atrial fibrillation and should instead be based on the presence of other previously identified risk factors.

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Citation Excerpt :
Clinical judgment is required when assessing risk of ACS with AF. Patient assessment and ECG before and after rate or rhythm control should be strongly considered in the evaluation of ACS [30-34]. Patients with significant ST changes after treatment require consideration for ACS.
Atrial fibrillation (AF) is an abnormal heart rhythm which may lead to stroke, heart failure, and death. Emergency physicians play a role in diagnosing AF, managing symptoms, and lessening complications from this dysrhythmia.
This review evaluates recent literature and addresses ED considerations in the management of AF.
Emergency physicians should first assess patient clinical stability and evaluate and treat reversible causes. Immediate cardioversion is indicated in the hemodynamically unstable patient. The American Heart Association/American College of Cardiology, the European Society of Cardiology, and the Canadian Cardiovascular Society provide recommendations for management of AF. If hemodynamically stable, rate or rhythm control are options for management of AF. Physicians may opt for rate control with medications, with beta blockers and calcium channel blockers the predominant medications utilized in the ED. Patients with intact left ventricular function should be rate controlled to <110 beats per minute. Rhythm control is an option for patients who possess longer life expectancy and those with AF onset <48 h before presentation, anticoagulated for 3–4 weeks, or with transesophageal echocardiography demonstrating no intracardiac thrombus. Direct oral anticoagulants are a safe and reliable option for anticoagulation. Clinical judgment regarding disposition is recommended, but literature supports discharging stable patients who do not have certain comorbidities.
Proper diagnosis and treatment of AF is essential to reduce complications. Treatment and overall management of AF include rate or rhythm control, cardioversion, anticoagulation, and admission versus discharge. This review discusses ED considerations regarding AF management.
Diagnostic Evaluation and Follow-Up of Patients with Atrial Fibrillation
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Managing Atrial Fibrillation
2015, Annals of Emergency Medicine
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One study found that ED atrial fibrillation patients without evidence of significant ST-segment changes were at very low risk for acute myocardial infarction.20 Another found that atrial fibrillation did not change the relative risk of an acute coronary syndrome in ED patients who had chest pain syndromes.21 We recommend using clinical judgment to rule out an acute coronary syndrome, including determining whether the chest pain started before or after the palpitations.
Diagnostic accuracy of electrocardiographic ST-segment depression in patients with rapid atrial fibrillation for the prediction of coronary artery disease
2014, Canadian Journal of Cardiology
We aimed to examine the diagnostic value of ST-segment depression in patients with rapid atrial fibrillation (AF) for the prediction of coronary artery disease (CAD).
Hemodynamically stable patients with AF, and a heart rate > 80% of their maximum predicted according to their age, were allocated to 2 groups according to their electrocardiographic findings on admission: group A included patients without any ST-segment abnormalities and group B, patients with downward or horizontal ST-segment depression ≥ 1 mm in 2 or more contiguous leads. Group A patients were subjected to a dobutamine stress echo or Tl-201 myocardial single-photon emission computed tomography, followed by coronary angiography in case of abnormal results and Group B patients to coronary angiography. CAD was defined angiographically as stenosis of ≥ 50% in any major epicardial coronary vessel.
Out of 115 consecutive patients, with a mean age of 65.9 ± 10.2 years, 42.6% were male, 18.3% smokers, 68.7% hypertensive, 21.7% had diabetes, and 40% had hyperlipidemia. We enrolled 71 and 44 patients in group A and B, respectively. Prevalence of significant CAD among studied patients was 21.7%, 3/71 (4.2%) and 22/44 (50.0%) in group A and B, respectively. Overall ST-segment depression during rapid AF had 88.0% sensitivity (95% confidence interval [CI], 67.7%-96.8%) and 75.6% specificity (95% CI, 65.2%-83.7%) in predicting presence of CAD, and positive and negative predictive value was 50.0% (95% CI, 34.8%-65.2%) and 95.8% (95% CI, 87.3%-98.7%), respectively.
In consecutive patients with rapid AF, the absence of ST-segment depression might indicate absence of CAD.
Notre but était d’examiner la valeur diagnostique de la dépression du segment ST pour prédire la coronaropathie (CP) chez les patients ayant une fibrillation auriculaire (FA) rapide.
Les patients hémodynamiquement stables ayant une FA et une fréquence cardiaque > 80 % de la prédiction maximale en fonction de leur âge étaient répartis en 2 groupes selon leurs résultats électrocardiographiques à l’admission : le groupe A comprenait les patients sans anomalies du segment ST, et le groupe B, les patients ayant une dépression descendante ou horizontale du segment ST ≥ 1 mm dans au moins 2 dérivations contiguës. Les patients du groupe A étaient soumis à une échocardiographie sous dobutamine ou à une imagerie de perfusion myocardique au T1-201 par tomographie par émission de photon unique suivie d’une coronarographie en cas de résultats anormaux, et les patients du groupe B, à la coronarographie. La CP était définie par l’angiographie par la quantification ≥ 50 % de sténose dans un vaisseau épicardique majeur.
Parmi les 115 patients consécutifs, dont l’âge moyen était de 65,9 ± 10,2 ans, 42,6 % étaient de sexe masculin, 18,3 % étaient des fumeurs, 68,7 % souffraient d’hypertension, 21,7 % avaient un diabète et 40 % avaient une hyperlipidémie. Nous avons inscrit respectivement 71 et 44 patients au groupe A et au groupe B. La prévalence de CP significative chez les patients étudiés était de 21,7 %, soit respectivement de 3/71 (4,2 %) et 22/44 (50,0 %) dans le groupe A et le groupe B. Dans l’ensemble, la dépression du segment ST durant la FA rapide avait une sensibilité de 88,0 % (intervalle de confiance [IC] à 95 %, 67,7 %-96,8 %) et une spécificité de 75,6 % (IC à 95 %, 65,2 %-83,7 %) pour prédire la présence de CP, et les valeurs prédictives positive et négative étaient respectivement de 50,0 % (IC à 95 %, 34,8 %-65,2 %) et de 95,8 % (IC à 95 %, 87,3 %-98,7 %).
Chez les patients consécutifs ayant une FA rapide, l’absence de dépression du segment ST indiquerait l’absence de CP.
Usefulness of a low CHADS2 or CHA2DS2-VASc score to predict normal diagnostic testing in emergency department patients with an acute exacerbation of previously diagnosed atrial fibrillation
2014, American Journal of Cardiology
Citation Excerpt :
We acknowledge that normal test results are often very important in managing patients with cardiovascular disease. However, physicians often search for an acute insult (e.g., acute coronary syndrome, electrolyte abnormality, and thyroid dysfunction) as the cause of an AF exacerbation despite such precipitants rarely being identified in patients without other concerning symptoms.26,30 This study was conducted at a single university-affiliated referral center with resident physicians, fellows, and faculty physicians staffing the ED.
International guidelines do not specify what testing should be performed during emergency department (ED) evaluations for patients presenting with an exacerbation of previously diagnosed atrial fibrillation (AF). We hypothesized that low CHADS2 and CHA2DS2-VASc scores predict normal routine diagnostic testing in these patients. We conducted an analysis within a prospective observational cohort study at a university-affiliated hospital. We included patients with previously diagnosed AF and who presented to the ED primarily for an AF-related complaint. Logistic regression was used to analyze the association between CHADS2 and CHA2DS2-VASc scores and abnormal results for blood counts, electrolytes, cardiac markers, thyroid function, and chest x-rays. We included 216 patients in this analysis. The odds ratios (95% confidence interval) for each point increase in CHADS2 for abnormal blood counts, electrolytes, troponin I, brain natriuretic peptide, thyroid function, and chest x-ray were 1.28 (0.99 to 1.65), 1.48 (1.19 to 1.84), 1.42 (1.10 to 1.82), 1.66 (1.15 to 2.41), 0.95 (0.70 to 1.29), and 1.17 (0.94 to 1.44), respectively. The corresponding odds ratios (95% confidence interval) for each point increase in CHA2DS2-VASc were 1.17 (0.96 to 1.42), 1.27 (1.09 to 1.49), 1.30 (1.07 to 1.57), 1.57 (1.18 to 2.10), 0.98 (0.79 to 1.22), and 1.14 (0.97 to 1.33), respectively. Among ED patients with established AF who underwent evaluation for acutely symptomatic AF, nearly 3/4 of routine diagnostic tests return to normal. In conclusion, patients with CHADS2 or CHA2DS2-VASc score of 0 have the lowest likelihood of abnormal studies and may represent an easily identifiable group of patients who need fewer ED tests.

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Original ContributionThe risk for acute coronary syndrome associated with atrial fibrillation among ED patients with chest pain syndromes

Abstract

Objective

Methods

Results

Conclusion

Introduction

Section snippets

Study design

Setting

Population characteristics

Discussion

Limitations

Conclusions

J Am Coll Cardiol

Am J Med

J Am Coll Cardiol

Am Heart J

Am J Cardiol

Am J Cardiol

Am J Cardiol

Ann Emerg Med

J Am Coll Cardiol

J Clin Epidemiol

Am J Cardiol

Emerg Med Clin North Am

Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) study

JAMA

Prevalence of atrial fibrillation and antithrombotic prophylaxis in emergency department patients

Stroke

Original Contribution
The risk for acute coronary syndrome associated with atrial fibrillation among ED patients with chest pain syndromes