Less Is More, More the Merrier, or More From Less?

P hysicians deal with uncertainty all the time and chest pain in the emergency department (ED) is a typical example. Traditionally, coronary artery disease (CAD), pulmonary embolism (PE), and aortic dissection can present as chest pain, and the consequences of a missed diagnosis can be devastating, with the potential for rapid deterioration, and serious risk of morbidity and mortality. Moreover, because these conditions are also common causes of malpractice claims, an extra layer of concern and possible overinvestigation may be added. This has led to a computed tomography angiography (CTA) strategy—the triple rule out (TRO) or a single test for all 3 conditions—out of an abundance of caution. Of course, CTA for a single diagnosis is routinely used in the ED. It is commonly used to exclude aortic dissection and CAD. It is often the first-line strategy to rule out pulmonary embolism (1,2), which is difficult to diagnose clinically and is often missed. Other tests for PE such as ventilation/perfusion scans are not robust and are diagnostic less than one-half of the time (2). This results in a low threshold for computed tomography (CT) evaluation but has a low positive yield with a very high negative predictive value (3). Overuse of CTA for PE in the ED is understandable but may be detrimental by picking up PEs that may not have immediate clinical relevance (1). An interesting paper (4) and the accompanying editorial (5) in this issue of iJACC on TRO by CTA for chest pain ED evaluation raise broader questions about the appropriate amount of testing in this