Emergency department and office-based evaluation of patients with chest pain

Abstract

The management of patients with chest pain is a common and challenging clinical problem. Although most of these patients do not have a life-threatening condition, the clinician must distinguish between those who require urgent management of a serious problem such as acute coronary syndrome (ACS) and those with more benign entities who do not require admission. Although clinical judgment continues to be paramount in meeting this challenge, new diagnostic modalities have been developed to assist in risk stratification. These include markers of cardiac injury, risk scores, early stress testing, and noninvasive imaging of the heart. The basic clinical tools of history, physical examination, and electrocardiography are currently widely acknowledged to allow early identification of low-risk patients who have less than 5% probability of ACS. These patients are usually initially managed in the emergency department and transitioned to further outpatient evaluation or chest pain units. Multiple imaging strategies have been investigated to accelerate diagnosis and to provide further risk stratification of patients with no initial evidence of ACS. These include rest myocardial perfusion imaging, rest echocardiography, computed tomographic coronary angiography, and cardiac magnetic resonance imaging. All have very high negative predictive values for excluding ACS and have been successful in reducing unnecessary admissions for patients at low to intermediate risk of ACS. As patients with acute chest pain transition from the evaluation in the emergency department to other outpatient settings, it is important that all clinicians involved in the care of these patients understand the tools used for assessment and risk stratification.

FIGURE 1.

Risk of myocardial infarction based on presenting characteristics. CAD = coronary artery disease; ECG = electrocardiography; MI = myocardial infarction. Data from N Engl J Med.

FIGURE 2.

Prevalence of diagnoses in patients with chest pain of unknown origin. Adapted from Eur Heart J, with permission from Oxford University Press.

FIGURE 3.

Use of acute myocardial perfusion imaging (MPI) in a risk stratification scheme. Risk of cardiac events, either myocardial infarction (MI) or the combination of MI and revascularization, increased as risk level increased from level 4 to 2. Patients who had positive findings on MPI had an event rate similar to level 2 patients (high-risk acute coronary syndrome). NS = not significant. Adapted from Ann Emerg Med, with permission from Elsevier.

FIGURE 4.

Schematic of patient distribution based on whether patients were randomized to acute computed tomographic coronary angiography (CTCA) or standard of care, which uses stress myocardial perfusion imaging (MPI) as the preferred risk stratification method. Adapted from J Am Coll Cardiol, with permission from Elsevier.