CORONARY CT IN EMERGENCY EVALUATION

CTA in the ER Can Safely and Effectively Screen for Acute Coronary Syndrome

Findings from a new study suggest that computed tomography angiography (CTA) safely and effectively stratifies high- and low-risk patients admitted to the emergency room for chest pain [1]. Investigators screened patients admitted to the emergency room for acute coronary syndrome using high-resolution CTA and showed that negative scans were a quick and accurate way of identifying patients who were safe to be discharged from the hospital.

"If you look at the literature, CTA is a relatively new technology," said lead investigator Dr Anna Marie Chang (University of Pennsylvania, Philadelphia). "Most people aren't using it in the emergency department to make decisions about the patient. Most people using it in this way are still testing it out, trying to see if it's okay, but we're using CTA in the low-risk patient. These are patients who traditionally would come into the emergency department and we'd have to admit them to the hospital or send them to observation unit before they could be sent home. Now we can send them home immediately from the emergency department."

The results of the study were presented here at the Society of Academic Emergency Medicine (SAEM) 2008 Annual Meeting.

Cutting costs by sending low-risk patients home

Speaking with heartwire, Chang said that approximately 5% to 15% of individuals admitted to the hospital for chest pain have an acute coronary syndrome, but more than half of these patients are admitted to the hospital for observation and further testing. While previous studies have traditionally compared CTA with other ACS screening protocols to determine how well it stacked up against these traditional tests, Chang and colleagues wanted to determine whether CTA could be used clinically to quickly and accurately determine whether patients could be discharged.

Investigators evaluated 568 patients with chest pain admitted to the Hospital of the University of Pennsylvania for acute coronary syndromes. Of these patients, 285 received CTA immediately in the emergency department and 283 received coronary CTA after a brief observation period. Overall, 84% of patients were discharged home following coronary CTA.

Investigators report that negative scans were accurate and allowed investigators to safely discharge patients from the hospital. Thirty days after discharge, none of 285 patients who received a coronary CTA immediately in the emergency department and were discharged died from cardiac causes, had an MI [myocardial infarction], or returned to the hospital for revascularization.

In terms of cost, Chang and colleagues report that CTA is more cost-effective than traditional methods of identifying at-risk patients [2]. In another study of 643 patients, also presented at the SAEM meeting, investigators compared the costs of receiving CTA in the emergency room with the costs associated with CTA following time in an observation unit, as well as with the costs of stress tests and telemetry monitoring following hospital admission.

The cost of screening with immediate CTA in the emergency room was $1240, while the cost of stress testing, measuring serial biomarkers, and monitoring in the observation unit was more than $4000 per patient. The cost of usual care, defined as admission with serial biomarkers and hospital-directed evaluation, was $2913. Among these low-risk patients without ACS, immediate CTA helped discharge patients faster, with these patients discharged an average of eight hours following admission. Those who were screened with stress testing and received telemetry monitoring were kept, on average, 24 hours.

"Not only is it a safe test, but it's less expensive," said Chang. "Patients are getting out of the emergency department much faster, which is important because of issues related to overcrowding. If a patient can leave the department in eight hours rather than 20 hours or more while waiting for a bed, this can free up more time for us to see other patients."

Chang told heartwire that if a hospital has the technology and the hospital administration is supportive of CTA in the emergency department, with radiologists trained in cardiac imaging to read the CTA scan, the test can routinely be used in clinical practice.

She noted there is currently a debate about reimbursement, with the Center for Medicare & Medicaid Services voting in November 2007 to not reimburse CTA use in the emergency room, although this decision was overturned. As previously reported by heartwire, all 50 individual US states already provide Medicare coverage for patients undergoing cardiac CTA under local coverage determinations, but the overturned federal policy decision would have limited Medicare coverage of a diagnostic CT to just two indications and only in cases where the patient was enrolled in a clinical trial of cardiac CT.