The NEW ENGLAND JOURNAL f MEDICINE REATMENT OF PATIENTS WITH ACUTE tial CCTA or standard evaluation without CCTA chest pain but an inconclusive initial evalu- patient care in both groups was not mandated by ation with the use of biomarkers and elec the study protocol but instead was at the discretio agnos it nging and majori ihed in ne disease.Contrast-enhanced this article at NEIM.org coronary computed tomographic angiogra phy (CCTA)has high sensitivity and specificity for the STUDY POPULATION detection of clinically significant coronary artery Patient enrollment began on April 23,2010,and on January 30 at nine on Un 。25 Rule out my dial e n to p n the ter Assisted Tomography (ROMICAT-D).a ROMICAT-I study6 with the goal of enrolling blinded observational study involving patients in population with a similar prevalence of acute the emergency departmen with suspected acute coronary syndromes (approximately 8%).Eligibl coronary syndromes and other studies? hav patients were 40 to 74 years of age,presented to wn th A have e emergency depar che pain ng out acu es thin 24 bou ion and the occurrence of maior adverse cardio ency department.we in sinus rhythn vascular events over the next 2 years.The results and wa arranted further risk stratification to rule of two previous randomized,multicenter trials out acute coronary syndromes,as determined by suggest that CCTA may facilitate safe and earlie an attending physician in the emergency depart triage of low-risk patients and that CCTA can ru ment.Major ex story o out co th stres is coronary arte th tile ures and greater costs than functional tes the local impaired t ngThus.equipoise exists regarding the effec nine level,>1.5 mg per deciliter [132.6 umol per tiveness of incorporating CCTA into an evaluation liter)),hemodynamic or clinical instability,known e allergy to an iodinated contrast agen the .comp nass index weight in kilograms divided b n stra th that of 0 me sthgreater tha egy dep ment for ants with s stive of an acute coronary syndrome and to STUDY PROTOCOL evaluate the downstream testing.cost,and radia- Eligible patients were identified,provided writter tion exposure associated with CCTA. informed consent,and were randomly assigned at their initial evaluation in th emergency depar METHODS ng 1e er CCT STUDY DESIGN AND OVERSIGHT itial ROMICAT-II was designed as arandomized.cor artme at or the standard evaluatio trolled,multicenter trial in which an evaluation and in the emergency department at that site all tes management strategy that included CCTA as a results were provided to emergency department first diagnostic test performed as early as possi physicians in real tim wa compa rgency mand Hated by the study protocol in partment evalua nts with acu an nt.Tas base ed on the lo 300 N ENGLJ MED 367:4 NEJM.ORG JULY 26,201 T h e n e w e ngl a nd j o u r na l o f m e dic i n e 300 n engl j med 367;4 nejm.org july 26, 2012 Treatment of patients with acute chest pain but an inconclusive initial evalu￾ation with the use of biomarkers and elec￾trocardiographic (ECG) testing is often diagnosti￾cally challenging and inefficient. The majority of patients with acute coronary syndromes have under￾lying coronary artery disease.1 Contrast-enhanced coronary computed tomographic angiography (CCTA) has high sensitivity and specificity for the detection of clinically significant coronary artery disease, as compared with invasive coronary angi￾ography, in patients in stable condition with sus￾pected or known coronary artery disease.2-5 Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT-I),6 a blinded observational study involving patients in the emergency department with suspected acute coronary syndromes, and other studies7,8 have shown that normal findings on CCTA have a very high negative predictive value for ruling out acute coronary syndromes during the index hospitaliza￾tion and the occurrence of major adverse cardio￾vascular events over the next 2 years.7,9 The results of two previous randomized, multicenter trials10,11 suggest that CCTA may facilitate safe and earlier triage of low-risk patients and that CCTA can rule out coronary artery disease faster than stress myocardial-perfusion imaging. However, imaging the coronary anatomy with CCTA can involve more procedures and greater costs than functional test￾ing.12 Thus, equipoise exists regarding the effec￾tiveness of incorporating CCTA into an evaluation strategy in the emergency department. The objectives of this study were to compare the effectiveness of a CCTA-based evaluation strat￾egy with that of standard evaluation in the emer￾gency department for patients with symptoms suggestive of an acute coronary syndrome and to evaluate the downstream testing, cost, and radia￾tion exposure associated with CCTA. Me thods Study Design and Oversight ROMICAT-II was designed as a randomized, con￾trolled, multicenter trial in which an evaluation and management strategy that included CCTA as a first diagnostic test performed as early as possible was compared with a standard emergency de￾partment evaluation for patients with acute chest pain suggestive of an acute coronary syndrome. After random assignments had been made to ini￾tial CCTA or standard evaluation without CCTA, patient care in both groups was not mandated by the study protocol but instead was at the discretion of local physicians. The design of ROMICAT-II has been described in detail previously,13 and the study protocol is available with the full text of this article at NEJM.org. Study Population Patient enrollment began on April 23, 2010, and ended on January 30, 2012, at nine hospitals in the United States. All patients provided written informed consent to participate in the study. Eli￾gibility criteria were chosen according to the ROMICAT-I study,6 with the goal of enrolling a population with a similar prevalence of acute coronary syndromes (approximately 8%). Eligible patients were 40 to 74 years of age, presented to the emergency department with chest pain (or the anginal equivalent) of at least 5 minutes’ du￾ration within 24 hours before presentation in the emergency department, were in sinus rhythm, and warranted further risk stratification to rule out acute coronary syndromes, as determined by an attending physician in the emergency depart￾ment. Major exclusion criteria were a history of known coronary artery disease, new diagnostic ischemic changes on the initial ECG, an initial troponin level in excess of the 99th percentile of the local assay, impaired renal function (creati￾nine level, >1.5 mg per deciliter [132.6 µmol per liter]), hemodynamic or clinical instability, known allergy to an iodinated contrast agent, a body￾mass index (the weight in kilograms divided by the square of the height in meters) greater than 40, or currently symptomatic asthma. Study Protocol Eligible patients were identified, provided written informed consent, and were randomly assigned at their initial evaluation in the emergency depart￾ment during weekday daytime hours. Patients were randomly assigned in a 1:1 ratio to either CCTA as part of the initial evaluation in the emergency department or the standard evaluation strategy in the emergency department at that site. All test results were provided to emergency department physicians in real time. Additional care was not mandated by the study protocol in either ran￾domization group. The discharge diagnosis was based on the lo￾cal physicians’ assessment. The discharge diag-