Coronary Computed Tomographic Angiography

Case presentation: A 55-year-old man presents to the emergency department (ED) after an episode of substernal chest discomfort that lasted 2 hours. His pain occurred at rest and was not positional, pleuritic, or postprandial. He has a history of hypertension and no known coronary artery disease (CAD). Vital signs and physical examination are unremarkable. His initial ECG, troponin, and serum creatinine are normal. How should this patient be evaluated?Chest pain is a common complaint in the ED, accounting for 10% to 15% of visits at an annual cost of $8 billion in the United States.1 However, missed myocardial infarctions occur in up to 2% of patients with acute chest pain2 and represent a leading cause of malpractice litigation. Because history alone is often inadequate to identify patients who may be safely discharged,3 it is common practice to use observation and serial cardiac biomarkers for patient evaluation. Additionally, exercise testing and vasodilator stress testing are commonly used, although such testing can be performed only after an observation period, which includes serial cardiac biomarkers. With increasing use of cardiac testing in an era of cost containment, a growing need exists to improve the efficiency and cost associated with the evaluation of acute chest pain.Coronary computed tomographic (CT) angiography (CTA) is a high-resolution, noninvasive technique to image the coronary arteries and to detect the presence, severity, and extent of CAD.4 The greatest utility of CTA lies in its high negative predictive value (≥95%) to exclude obstructive CAD and thus to identify patients who can be safely discharged without further diagnostic testing.5 In addition, this test can be performed rapidly because only 1 set of negative biomarkers is needed. Consequently, 4 randomized, controlled trials in the ED have compared CTA with usual care6–8 and …