Evaluation of chest pain in the emergency department

Abstract

The evaluation of chest pain in the emergency setting should be systematic, risk based, and goal driven. An effective program must be able to evaluate all patients with equal thoroughness under the assumption that any patient with chest pain could potentially be having an MI. The initial evaluation is based on the history, a focused physical examination, and the ECG. This information is sufficient to categorize patients into groups at high, moderate, and low risk. Table 14 is a template for a comprehensive chest-pain evaluation program. Patients at high risk need rapid initiation of appropriate therapy: thrombolytics or primary angioplasty for the patients with MIs or aspirin/heparin for the patients with unstable angina. Patients at moderate risk need to have an acute coronary syndrome ruled in or out expediently and additional comorbidities addressed before discharge. Patients at low risk also need to be evaluated, and once the likelihood of an unstable acute coronary syndrome is eliminated, they can be discharged with further evaluation performed as outpatients. Subsequent evaluation should attempt to assign a definitive diagnosis while also addressing issues specific to risk reduction, such as cholesterol lowering and smoking cessation. It is well documented that 4% to 5% of patients with MIs are inadvertently missed during the initial evaluation. This number is surprisingly consistent among many studies using various protocols and suggests that an initial evaluation limited to the history, physical examination, and ECG will fail to identify the small number of these patients who otherwise appear at low risk. The solution is to improve the sensitivity of the evaluation process to identify these patients. It appears that more than simple observation is required, and at the present time, no simple laboratory test can meet this need. However, success has been reported with a number of strategies including emergency imaging with either radionuclides such as sestamibi or echocardiography. Early provocative testing, either stress or pharmaceutic, may also be effective. The added value of these tests is only in their use as part of a systematic protocol for the evaluation of all patients with acute chest pain. The initial evaluation of the patient with chest pain should always consider cardiac ischemia as the cause, even in those with more atypical symptoms in whom a cardiac origin is considered less likely. The explicit goals for the evaluation of acute chest pain should be to reduce the time to treat MIs and to reduce the inadvertent discharge of patients with occult acute coronary syndromes. All physicians should become familiar with appropriate risk stratification of patients with acute chest pain. Systematic strategies must be in place to assure rapid and consistent identification of all patients and the expedient initiation of treatment for those patients with acute coronary syndromes. These strategies should include additional methods of identifying acute coronary syndromes in patients initially appearing as at moderate or low risk to assure that no unstable patients are discharged. All patients should be followed up closely until the cardiovascular evaluation is completed and, when possible, a definitive diagnosis is determined. Finally, this must be done efficiently, cost-effectively, and in a manner that will result in an overall improvement in patient care.