Chicago, IL—The evaluation of patients presenting to the emergency department with symptoms of an acute coronary syndrome (ACS) with coronary computed tomography angiography (CTA) resulted in faster diagnosis, shorter length of stay, and more direct discharge compared with standard evaluation, according to Udo Hoffmann, MD, MPH, Cardiac Radiologist, Director of Cardiac Imaging, Massachusetts General Hospital, Boston, and lead investigator of the multicenter study Rule Out Myocardial Infarction by Computer-Assisted Tomography (ROMICAT) II.
In ROMICAT II, 1000 patients (mean age, 54 years) at 9 centers were randomized to CTA or standard evaluation by a local physician. The length of hospital stay, the primary end point, was significantly shorter with CTA: 23 hours compared with 30 hours with standard evaluation. This difference was driven by the shorter length of stay in the patients who were not diagnosed with ACS (17.2 hours vs 27.2 hours, respectively). In patients diagnosed with ACS, the length of stay was similar.
Cost Results Mixed
The cost data were mixed. Although costs were reduced for the emergency department with CTA compared with standard evaluation, hospital costs were higher with CTA, and total costs were similar for both strategies (Table).
The investigators were pleased to see that total costs were similar, because Medicare data suggested there was a doubling in procedures and costs after CTA compared with function testing in the observational ROMICAT I study. However, CTA examination was limited in ROMICAT II to business weekday hours; expansion to 24-hour availability could impact costs.
With a 1-second scan, CTA can accurately and noninvasively determine the extent of coronary artery disease (CAD), whereas standard evaluation typically requires 24 to 36 hours and requires additional work-up to rule out CAD. CTA has been shown to have a high predictive value for ruling out CAD. ROMICAT I showed that patients presenting with chest pain had a low 8% prevalence of ACS, that most patients did not have CAD or obstructive plaque, and that CTA had a very high negative predictive value to predict events over the next 2 years.
Of note, in ROMICAT II, early CTA led to advanced discharge in patients without an ACS diagnosis. Of patients undergoing CTA, 50% were discharged within 8 hours compared with 28 hours with standard evaluation, said Dr Hoffmann. A diagnosis of ACS was made in 8.6% of patients who had CTA and in 6.4% of the standard-evaluation patients.
Care and Discharge Differences
Direct discharge rate from the emergency department was 4-fold higher with CTA (46%) than with standard evaluation (12%). Fewer patients in the CTA arm were admitted to the hospital. The time to diagnosis was shorter by approximately 8 hours with CTA for patients with and without ACS (10 hours vs 18.7 hours with standard evaluation). Repeat visits to the emergency department for chest pains were reduced 13% with CTA compared with 19% with standard evaluation.
Testing was significantly higher in the clinical trial arm, and was primarily driven by the higher number of patients in the standard-evaluation arm who did not have any tests (22% vs 2%, respectively). More patients who had CTA had 1 test (75%) and >2 tests (23%) compared with 67% and 10.6% of the standard-evaluation arm.
There was no missed ACS diagnoses in either arm. Two periprocedural complications occurred in the CTA arm. At 28 days, 2 major adverse events (defined as death, myocardial infarction, unstable angina pectoris, or the need for urgent revascularization) occurred in the CTA group and 5 in the standard-evaluation arm.
Invasive coronary angiography was performed in 12% of the CTA patients and 8% of the standard-evaluation patients. There were also more interventions (6.4%) in the CTA arm than with standard evaluation (4.2%).