EVOLUTION IN THE MANAGEMENT OF LOW RISK PATIENTS PRESENTING TO THE EMERGENCY DEPARTMENT WITH CHEST PAIN
Ezra A. Amsterdam, M.D., University of California (Davis) Medical Center, Sacramento, CA, USA
The majority of patients presenting to the ED with chest pain comprise a low risk population who do not have acute coronary syndrome (ACS) or other life threatening condition. Therefore, most at are low risk for morbidity and mortality. Such low risk patients are usually identified by absence of a history of cardiovascular disease, normal or nonischemic ECG, normal initial troponin, and clinical stability. The utility of accelerated diagnostic protocols (ADP) has been established for further confirmation of low clinical risk and appropriateness for direct discharge from the ED versus detection of higher risk patients who require admission. At minimum, these protocols entail serial ECGs and measurement of cardiac injury markers, both of which can be performed in the ED or a chest pain observation unit. Negative results have usually been followed by a cardiac functional (treadmill test or stress imaging evaluation) or anatomic study (cardiac computed tomography angiography Card [cardiac CTA or MRI) to enhance the safety of early discharge. These ADPs have been associated with a negative predictive value at 30 days greater than 99% for ACS or other major cardiovascular event. Several recent protocols for evaluation of low risk patients have been reported, such as a 2hr evaluation comprising a TIMI risk score of 0, normal ECGs, and normal hs-TnI. Cardiac CTA has a very high negative predictive value and has been performed without prior measurement of troponin. Currently, the ADP is in evolution with recent reports indicating excessive testing of low risk patients and more reliance on physician discretion for functional or anatomic testing with maintenance of safety and negative predictive value. This approach has also resulted in shorter length of stay in the ED or observation unit (<6 hr) and lower cost.