Coronary computed tomography angiography for early triage of patients with acute chest pain: the ROMICAT (Rule Out Myocardial Infarction using Computer Assisted Tomography) trial

Abstract

Objectives: This study was designed to determine the usefulness of coronary computed tomography angiography (CTA) in patients with acute chest pain.

Background: Triage of chest pain patients in the emergency department remains challenging.

Methods: We used an observational cohort study in chest pain patients with normal initial troponin and nonischemic electrocardiogram. A 64-slice coronary CTA was performed before admission to detect coronary plaque and stenosis (>50% luminal narrowing). Results were not disclosed. End points were acute coronary syndrome (ACS) during index hospitalization and major adverse cardiac events during 6-month follow-up.

Results: Among 368 patients (mean age 53 +/- 12 years, 61% men), 31 had ACS (8%). By coronary CTA, 50% of these patients were free of coronary artery disease (CAD), 31% had nonobstructive disease, and 19% had inconclusive or positive computed tomography for significant stenosis. Sensitivity and negative predictive value for ACS were 100% (n = 183 of 368; 95% confidence interval [CI]: 98% to 100%) and 100% (95% CI: 89% to 100%), respectively, with the absence of CAD and 77% (95% CI: 59% to 90%) and 98% (n = 300 of 368, 95% CI: 95% to 99%), respectively, with significant stenosis by coronary CTA. Specificity of presence of plaque and stenosis for ACS were 54% (95% CI: 49% to 60%) and 87% (95% CI: 83% to 90%), respectively. Only 1 ACS occurred in the absence of calcified plaque. Both the extent of coronary plaque and presence of stenosis predicted ACS independently and incrementally to Thrombolysis In Myocardial Infarction risk score (area under curve: 0.88, 0.82, vs. 0.63, respectively; all p < 0.0001).

Conclusions: Fifty percent of patients with acute chest pain and low to intermediate likelihood of ACS were free of CAD by computed tomography and had no ACS. Given the large number of such patients, early coronary CTA may significantly improve patient management in the emergency department.

Figures

Figure 1

A–C: 40-year old male who presented 3 hours after the onset of substernal chest pain and who had an inconclusive initial evaluation in the emergency department (ED) with non-diagnostic ECG and negative initial biomarkers. The patient was determined to have acute coronary syndrome (ACS) after troponin became positive (8 hours after ED presentation). The patient subsequently underwent invasive coronary angiography, where an 80% mid left anterior descending coronary artery (LAD) stenosis was detected, and subsequently a stent was placed. Coronary computed tomography angiography (CTA) was performed prior to hospital admission. This patient was classified as positive for the presence of significant coronary stenosis. A: Volume rendered 3-dimensional CT image of the heart depicting the right coronary artery (RCA, arrow) and the LAD (arrowhead). B: Maximum intensity projection (MIP) image of the RCA (arrowheads) demonstrating calcified and non-calcified plaque without the presence of a significant coronary stenosis and the LCX (arrows) demonstrating calcified and non-calcified plaque with proximal luminal narrowing. C: Curved multiplanar reformatted image of the LAD reveals a significant coronary stenosis (arrow) in the mid portion of the vessel. Proximal and distal portion demonstrate good luminal contrast enhancement with minimal coronary plaque.

Figure 2

Areas under the receiver-operating characteristic curves (AUC) for the detection of acute coronary syndrome (ACS) during index hospitalization. AUC were higher for both plaque and stenosis as compared to the TIMI risk score (AUC: 0.88, 0.82 vs. 0.63; respectively).