Diagnosis of patients presenting with acute chest pain, whose initial evaluation with biomarkers and electrocardiographic (ECG) testing is inconclusive, is often challenging and inefficient. The majority of patients with acute coronary syndromes have underlying coronary artery disease. In patients in stable condition with suspected or known coronary artery disease, contrast-enhanced coronary computed tomographic angiography (CCTA) can provide high sensitivity and specificity compared with invasive coronary angiography.
Studies have shown that normal findings on CCTA have a high negative predictive value for ruling out acute coronary syndromes during the index hospitalization as well as the occurrence of major adverse cardiovascular events over the next 2 years. Two randomized multicenter trials have suggested that CCTA may facilitate safe and earlier triage of low-risk patients and can rule out coronary artery disease faster than stress myocardial perfusion imaging.
Researchers recently conducted a trial designed to compare the effectiveness of a CCTA-based evaluation strategy with standard evaluation in the emergency department (ED) for patients with symptoms suggestive of an acute coronary syndrome. The trial also evaluated the subsequent testing, costs, and radiation exposure associated with CCTA. The researchers reported trial results in the New England Journal of Medicine [2012;367(4):299-308].
ROMICAT-II (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) was a randomized, controlled, multicenter trial. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the ED, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes.
Patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test were randomly assigned to early CCTA or to standard evaluation in the ED on weekdays during daylight hours between April 2010 and January 2012.
The rate of acute coronary syndromes among 1000 patients with a mean age of 54 years, 47% of whom were women, was 8%. Compared with standard evaluation, use of early CCTA reduced the mean length of stay in the hospital by 7.6 hours (P<.001). In addition, more patients in the CCTA cohort were discharged directly from the ED compared with standard evaluation (47% vs 12%, P<.001). Of note, 50% of the patients in the CCTA group were discharged within 8.6 hours after presentation, compared with 10% of the patients in the standard evaluation cohort.
At 28 days, there were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events. After CCTA, there was more downstream testing and higher radiation exposure. Nearly all of the patients (97%) in the CCTA group received radiation exposure from an imaging test or procedure compared with 33% of the patients in the standard evaluation group.
Cumulative mean cost of care was similar in the CCTA cohort and the standard evaluation cohort ($4289 and $4060, respectively; P=.65).
Study limitations cited by the researchers included limiting enrollment to weekly hours when all imaging testing was available with technologists and readers on site and the inability to generalize the results to clinical sites that performed a dedicated accelerated diagnostic protocol in the standard evaluation.
In conclusion, the researchers said, “In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care.”