Evaluation of Low-Risk Patients with Chest Pain in the Emergency Department Value and Limitations of Recent Methods

More than 2 million patients are hospitalized annually in this country because of chest pain suggestive of myocardial ischemia. However, a coronary event is demonstrated in <20% of this population. It has been further shown that among patients presenting with acute chest pain, a very low-risk group, with <5% probability of a coronary event, can be identified by the initial clinical assessment. Recognition of this group could prevent many unnecessary hospital admissions, affording more appropriate patient care and improved cost-effectiveness. To enhance identification and management of low-risk patients with chest pain, several diagnostic approaches are currently being investigated to determine their value in the early detection of myocardial ischemia to select those requiring admission. In addition to the initial history, these strategies include physical examination and electrocardiogram, new serum markers, early noninvasive cardiac imaging by echocardiography or myocardial scintigraphy, new electrocardiographic methods, and early exercise testing. Most of these methods have shown promise for stratifying patients presenting with chest pain into high-risk and low-risk groups, thereby extending the initial clinical assessment in the critical decision of patient admission or discharge from the emergency department with early follow-up. This review presents the current status of these techniques with emphasis on our experience with immediate treadmill testing of selected patients in the emergency department. These methods are still in the developmental phase and their long-term utility will be determined by their safety, accuracy, cost, and specific institutional expertise.