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Screening of acute chest pain patients in the emergency department with coronary computed tomographic angiography (CTA) safely hastens diagnosis and shortens hospital stay, according to a randomized study published in the July 26, 2012, issue of the New England Journal of Medicine. However, the improved efficiency comes at the cost of increased radiation exposure and more downstream testing and does not reduce overall hospital costs.

Findings from the ROMICAT-II (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) trial were originally presented in March 2012 at the annual American College of Cardiology/i2 Scientific Session in Chicago, IL.

The trial built on its predecessor, the observational ROMICAT-I study, which showed CTA’s high level of accuracy in ruling out ACS and the risk of MACE over 2 years in patients with normal coronary arteries.

For the follow-up multicenter trial, investigators led by Udo Hoffmann, MD, MPH, of Massachusetts General Hospital (Boston, MA), randomized 1,000 patients who presented to emergency departments with symptoms suggestive of ACS to coronary CTA (n = 501) or standard evaluation (n = 499). All patients were at intermediate risk of ACS.

Easier on Patients, Busy Emergency Departments

Overall, use of coronary CTA reduced the length of hospital stay (the primary endpoint) by 7.6 hours compared with standard evaluation. Early CTA screening also decreased the time to diagnosis and increased the percentage of patients discharged directly from the emergency department (table 1).

Table 1. Effectiveness of CTA vs. Standard Evaluation

The overall incidence of ACS was 8%. Importantly, the efficiency of CTA assessment came at no safety cost, as no patient (in either group) was found to have undetected ACS on follow-up. Moreover, rates of periprocedural complications and MACE at 28 days were similar for the CTA and standard evaluation arms.

In terms of resource utilization, more diagnostic testing was performed in the coronary CTA group than the standard evaluation group. CTA patients also tended to undergo invasive angiography more often during the index hospitalization or over follow-up. In addition, patients in the CTA arm received almost 3 times more radiation than those in the standard arm (only one-third of whom were exposed to any radiation from an imaging test or procedure).

In a subgroup analysis of 649 patients from 5 centers, emergency department costs were lower for CTA screening, but the total cost of care from presentation through 28-day follow-up was similar regardless of how patients were evaluated (table 2).

Table 2. Resource Utilization, Radiation Exposure, and Costs by Evaluation Strategy

^a Includes coronary CTA, exercise treadmill testing, SPECT, stress echocardiography, and invasive angiography.
^b Includes exposure from coronary CTA, SPECT, and invasive angiography.

For patients, knowing that they have almost even odds of not having to wait around in the emergency department for a workup is “a huge benefit,” Matthew J. Budoff, MD, of Harbor-UCLA Medical Center (Torrance, CA), told TCTMD in a telephone interview. And “with a fourfold faster throughput for chest-pain patients, [CTA screening] significantly improves the efficiency of emergency departments,” he added.

The latter result is important because it reduces the chances that other patients may be denied timely care, observed Gilbert L. Raff, MD, of William Beaumont Hospital (Royal Oak, MI), in a telephone interview with TCTMD. Greater efficiency also helps ease the financial burden that overcrowded emergency departments pose to hospitals, he noted.

A Matter of Experience?

As for the excess downstream testing seen in the CTA group, Dr. Budoff suggested it was due in part to overinterpretation of CT scans by less experienced readers, which led to unnecessary catheterization. “As the technology matures and readers gain more experience, that downstream cost will go away, [while] preserving the upstream cost savings in the emergency department,” he said.

Another likely contributor to the disparity in testing, Dr. Raff reported, is the fact that many patients in the standard evaluation group underwent no tests—a practice that is not evidence-based, he noted.

With regard to the potential for increased radiation exposure with CTA, Dr. Budoff observed that the technology is evolving rapidly, with dosages decreasing significantly every year. Moreover, he noted, CTA typically delivers less radiation than a nuclear stress test, which in many parts of the country is the most commonly used alternative for evaluating chest pain.

Longer Follow-up Needed

Dr. Budoff stressed the need to assess the longer-term impact of CTA screening on repeat hospitalizations and costs. “I think the ‘warranty period’ of CT compares favorably with treadmill testing or stress echo or stress nuclear,” he said. “We don’t trust [these methods] after about a year, whereas CT we tend to trust longer.”

Dr. Raff made the same point. Patients with normal CT scans are highly unlikely to have CAD and do not need further tests, he explained, while those who pass a stress test often return to the emergency department for repeat tests and ultimately undergo angiography.

“I was disappointed that ROMICAT-II didn’t show cost savings,” Dr. Budoff said, “but I think it will as we follow these patients longer.” Already Blue Cross, Blue Shield, which has been the most conservative of the payers with regard to CTA coverage, has issued a national tech assessment supporting the technology’s use in emergency departments, he reported.

Study Details

There was no difference in baseline demographics and clinical characteristics between the CTA and standard evaluation groups.

To ensure that cases of ACS did not go undetected, patients discharged within 24 hours of presentation to the emergency department were contacted within 72 hours and at 28 days post discharge.

Before the start of the study, participating sites were not routinely performing CTA in the emergency department to detect ACS, but they were required to use at least 64-slice CT technology for patient assessment.

Related Stories:

• Early Cardiac CTA Improves Decision-Making in Suspected ACS
• Coronary CTA Can Serve as Gatekeeper to Invasive Angiography
• Coronary CTA Use in Emergency Department Saves Time, Money