Routine Coronary CTA to Rule Out ACS in Acute Chest Pain Questioned in ROMICAT-II Subanalysis

Clinical evaluation alone is sufficient for determining whether patients presenting to the emergency department (ED) with chest pain, negative biomarkers, and a nonischemic ECG are having an acute coronary syndrome (ACS), according to a subanalysis of the ROMICAT-II trial. Compared with patients who had additional testing that included either imaging or stress testing, those who had no noninvasive testing had shorter lengths of stay at less cost. Importantly, no cases of ACS were missed and there was no difference in MACE rates in the month after evaluation.

David L. Brown, MD (Washington University School of Medicine, St Louis, MO), senior author of the new subanalysis, said that for ruling out ACS, the streamlined approach addresses the issue more directly and gets patients out of the ED sooner rather than later.

“These other tests . . . are not part of any algorithm for the diagnosis of unstable [angina] or acute coronary syndrome. They either directly or indirectly may make the diagnosis of coronary disease, but that’s not the goal of a patient who comes to the emergency room,” he said in an interview with TCTMD “In my mind, that’s the role of the outpatient doctor, whether it be a primary care doctor or a cardiologist.”

Brown added that having patients follow up with another physician in the outpatient setting once the acute chest pain episode subsides may be the best way to stop the “testing cascade” that seems to happen when patients are kept too long in the ED.

“Sometimes additional testing in the outpatient setting might be appropriate, but it needs to be done with the understanding of what the goal is and with the patient involved in the decision-making with someone who knows them a little bit better than an ED doctor who met them 5 minutes ago,” he said.

But Matthew J. Budoff, MD (Harbor-UCLA Medical Center, Torrance, CA), who commented on the study for TCTMD, expressed concerns about the subgroup analysis, which is based on 118 patients who were randomized and consented into ROMICAT-II but who received no testing.

“These findings are interesting but meaningless as far as being able to draw strong conclusions,” he observed. “They are contrary to the overall results of ROMICAT-II and [while] they may warrant a prospective study to look at this further, it’s important to be cautious about interpreting subgroup data.”

Shorter Lengths of Stay, Less Radiation Exposure, and Lower Costs

The main ROMICAT II trial randomized 1,000 patients who presented to the ED with symptoms suggestive of ACS but without ischemic ECG changes or a positive troponin test result to coronary CTA or standard evaluation. All patients were at intermediate risk of ACS. The study authors concluded that coronary CTA reduced length of stay by 7.6 hours compared with standard evaluation, reduced the time to diagnosis, and resulted in a fourfold increase in the percentage of patients discharged directly from the ED.

For the post hoc analysis published online November 14, 2017, in JAMA Internal Medicine, the researchers led by Samuel W. Reinhardt, MD (Washington University School of Medicine), looked at the 12% of patients from ROMICAT-II who received no noninvasive testing during their ED stay and compared them with the other 88%. The former group included nine patients originally randomized to coronary CTA who did not undergo the test, and 109 patients randomized to standard care. Brown said the ROMICAT-II authors did not elaborate on why patients whose intent-to-treat assignment was coronary CTA did not undergo the procedure.

Compared with the group receiving clinical evaluation plus noninvasive testing, those who received evaluation alone had shorter lengths of stay (20.3 hours vs 27.9 hours; P < 0.001), less diagnostic testing and angiography, lower median ED costs at the index visit ($1,467.30 vs $1,944.80; P < 0.001), lower median total costs ($2,261.50 vs $2,584.30; P = 0.009), and lower cumulative radiation exposure (0 vs 9.9 mSv; P < 0.001). After discharge, there was no difference between the two groups in rates of PCI or CABG, and no difference in the number of return visits over 28 days of follow-up.

Despite the apparently shorter length of stay for the no-testing patients, Budoff pointed out that in the original ROMICAT-II trial the median length of stay for the group randomized to coronary CTA was 8.6 hours compared with 26.7 hours for the standard evaluation group. By blending patients from the two groups who were randomized but did not receive any testing, Budoff said it is possible that the effect of coronary CTA might have gotten lost. Either way, he said he believes the subgroup analysis is too weak to stand on its own and questioned why none of the ROMICAT-II investigators were involved with it.

Missed MIs and Radiation Exposure

“While the findings are suggestive that testing may safely be omitted in such patients, the results are not definitive,” says Gregory Curfman, MD (Harvard Medical School, Boston, MA), in an accompanying editor’s note. “The study was not designed or powered to address this question, and patients were not randomized to testing or no testing.”

Curfman adds that the results should motivate a randomized clinical trial of noninvasive testing, and he suggests that until then, “clinicians may wish to consider following patients with low-risk chest pain and reserving noninvasive testing if indicated by subsequent events.”

To TCTMD, Brown said that is how he practices now, and feels the study results affirm the validity of taking that position. As far as further randomized trials are concerned, he said studies of coronary CTA versus stress testing should either be discontinued or include a basic evaluation arm with no testing.

In their paper, Brown and colleagues say current guidelines that recommend noninvasive anatomic or functional testing to reduce the rate of missed MI are “misguided,” adding that the widespread adoption of troponin testing has likely reduced rates of missed MI since the guidelines were written.

They also stress that the potential harm from radiation exposure via coronary CTA should be factored into decision-making, especially with regard to lifetime cancer risk in younger patients.

“The risk of cancer, in addition to increased healthcare costs, demands that the benefits of noninvasive testing associated with radiation be demonstrated in randomized clinical trials,” Brown and colleagues write.