This study was designed to determine the usefulness of coronary computed tomography
angiography (CTA) in patients with acute chest pain.
Triage of chest pain patients in the emergency department remains challenging.
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.
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).
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.