Use of coronary CT angiography (CCTA) in evaluating patients with suspected acute coronary syndromes improved the efficiency of clinical decision making in the ED, with patients experiencing shorter hospital stays and more direct discharges from the ED than with the standard, non-CCTA evaluation strategy, according to a study published July 26 in the New England Journal of Medicine.

These gains in efficiency didn’t come at the cost of patient safety, as there were no undetected acute coronary syndromes using CCTA evaluation, explained Udo Hoffmann, MD, MPH, of Massachusetts General Hospital in Boston, and colleagues.

“What the study does is show CT is really a viable alternative to other strategies,” Hoffmann said in an interview.

Hoffmann et al explained that inconclusive initial evaluation of patients with chest pain using biomarkers and ECG testing is diagnostically challenging and inefficient. To compare the standard evaluation with a CCTA-based strategy, the authors conducted a multicenter trial featuring patients aged 40 to 74 who were experiencing symptoms of acute coronary syndromes but were without ischemic electrocardiographic changes or an initial positive troponin test.

A total of 1,000 patients were randomly assigned to one of the evaluation strategies between April 2010 and January 2012, and major adverse cardiovascular events within 28 days of evaluation were tracked.

The overall rate of acute coronary syndromes in the study population was 8 percent. Results showed that a CCTA-based evaluation strategy reduced the length of hospital stays by an average of 7.6 hours compared with a non-CCTA initial evaluation. Forty-seven percent of patients in the CCTA evaluation group were discharged directly from the ED, compared with 12 percent of patients who underwent a standard initial observation.

No acute coronary syndromes went undetected and there were no significant differences between evaluation strategies in the number of major adverse cardiovascular events at 28 days. There was more subsequent testing performed in the CCTA group than the standard evaluation group.

“Information on the presence of anatomical coronary artery disease may influence clinical decision making toward invasive angiography,” wrote the authors. Despite a higher likelihood of subsequent testing in the CCTA group, data from sites where complete billing information was available showed the cumulative cost of care of the two strategies was similar.

Hoffmann said one unique aspect of the current study is that it focused on sites which did not perform CT prior to the study, whereas previous research into CCTA largely involved CT specialists. Data from the study could help providers understand how processes will work once they start a CCTA program, and could alter patient preferences as well.

“If I were a 55-year-old male with chest pain, I would be interested to know as quickly as possible whether it’s a heart attack or not,” said Hoffmann.

In an accompanying editorial, Rita F. Redberg, MD, of the University of California, San Francisco, challenged what she described as the “underlying assumption” of Hoffmann et al that some kind of diagnostic test must be performed in low and intermediate risk patients before discharging them from the ED. She wrote that the rationale for a test should be that it leads to an improved outcome compared with not testing, and the current study did not show whether the CCTA groups received any benefit.

Redberg said decisions about the need for additional diagnostic testing in patients with normal ECG findings and negative troponin levels can usually be deferred to an outpatient follow-up in the weeks after the ED visit. Hoffmann and colleagues did indeed demonstrate that it’s faster to perform a CCTA than a stress test, she said.

“Of course, it is even faster to discharge these patients without any additional diagnostic test after determining that their ECG findings and troponin levels are normal. Thus, with no evidence of benefit and definite risks, routine testing in the emergency department of patients with a low-to-intermediate risk of acute coronary syndromes should be avoided.”