ACC: CCTA can improve chest pain diagnoses without increased costs
CHICAGO—Using cardiac CT angiography (CCTA) early on in the presentation of chest pain may more accurately assess patients who should be admitted for MI, according to the results of the late-breaking ROMICAT II trial presented March 27 at the 61st annual American College of Cardiology (ACC) scientific session. Additionally, CCTA resulted in a reduction of length of stay at essentially no increased cost.

ROMICAT II (Rule Out Myocardial Ischemia/Infarction Using Computer Assisted Tomography) was a randomized multicenter trial that aimed to compare the use of CCTA and standard methods to evaluate acute chest pain patients in the emergency department (ED).

“This allowed us to look at new technologies that can help address problems in our healthcare system,” said the study’s lead author, Udo Hoffmann, MD, MPH, director of cardiac imaging at Massachusetts General Hospital in Boston, during a press conference.

“Chest pain that is suggestive of ACS is one of the most common presentations to the ED,” Hoffmann said during the morning presentation. He noted that current strategies used to help rule out ACS are “inefficient,” and often help to overcrowd EDs and move unnecessary hospital admissions forward.

Despite improvements in healthcare, an estimated 2 percent of these chest pain patients are being discharged from the hospital with ACS, Hoffmann noted.

“What was not possible before has become possible since the early 2000s, and that is the noninvasive visualization of coronary artery disease,” offered Hoffmann. This has become possible with the help of CCTA.

Prior to ROMICAT II, the researchers performed ROMICAT I, which was a blinded observational study of CCTA in acute chest pain patients who were at low- or intermediate-risk for ACS. They found that most of these patients had no CAD or obstructive plaque and had a very high negative predictive value for events in the next two years.

While Hoffmann noted that there has been promising data suggesting CCTA may facilitate an earlier ED triage and reduce length of stay, Medicare data have also shown that CCTA has the potential to double costs.

For ROMICAT II, Hoffmann et al randomized 1,000 patients to receive early CCTA (501 patients) or standard ED evaluation (499 patients) to evaluate whether the addition of CCTA could improve clinical decision making.

While the study's primary endpoint was length of stay, the researchers also evaluated the rates of missed ACS, costs of care and resource utilization. Additionally, they assessed radiation exposure.

The researchers performed a follow-up phone call 48-72 hours after evaluation. Patients were between the ages of 40 and 74 and had chest pain symptoms suggestive of ACS.

Hoffmann reported length of stay to be 23.2 days in the CCTA arm compared with 30.8 days in the standard evaluation arm. “There was a highly significant shortening of length of stay in the CT arm as compared to the standard ED arm,” Hoffmann said. “We detected a difference of 8.3 hours.”

Hoffmann reported that there was 3,018 hours saved with CCTA compared with standard evaluation. Additionally, he said that while it took an estimated 8.6 hours to discharge patients in the CCTA arm, discharge took nearly 30 hours for patients in the standard care arm. Patients who were evaluated with CCTA spent 18 less hours in the hospital.

“We did not see any missed cases of ACS in the trial,” Hoffmann noted. However, there were two periprocedural complications in the CCTA arm compared to zero in the standard evaluation arm. Of the patient cohort, 46.7 percent of CCTA patients were directly discharged from the ED compared with only 12.4 percent of patients in the standard evaluation arm.

More testing occurred in the patients who received CCTA. “More testing is done when you get a cardiac CT because CT is very sensitive in the detection of CAD,” Hoffmann said. “Therefore, there was more testing in patients who had disease and less in patients who did not have disease.”

Despite previous study results, the current study found similar costs to the hospital in both arms. “The cost of an emergency department stay was less in the CCTA arm,” Hoffmann noted. These costs were $2,053 vs. $2,532, respectively, from CCTA and standard care. The costs per hospital stay were $1,950 vs. $1,297, respectively.

“In ED patients with chest pain suggestive of ACS, an evaluation strategy incorporating early CCTA significantly reduces length of stay and time to diagnosis,” Hoffmann summed. Additionally, the strategy can help to reduce ED discharge rates and cut down on the number of missed ACS cases.

“Previous trials have not been able to grasp the full association of implementing CT to discharge patients early to bring patients in more quickly,” Hoffmann added. “The collateral affect of this could be argued to be equally as important.”  

The panelists discussed the increased radiation dose found in CCTA arm of the study (14.3 mSv vs. 5.3 mSv). Hoffmann said that advanced imaging techniques, such as higher slice CT scans, can allow scanning to occur between the areas of 1-3 mSv.

ROMICAT II was funded by National Heart, Lung, and Blood Institute of the National Institutes of Health.