Tessa S. S. Genders

Several non-invasive imaging techniques are currently in use for the diagnostic workup of adult patients with stable chest pain suspected of having coronary artery disease (CAD). In this paper, we present a systematic overview of the evidence on diagnostic performance and comparative cost-effectiveness of new modalities in comparison to established technologies. A literature search for English language studies from 2009 to 2013 was performed, and two investigators independently extracted data on patient and study characteristics. The reviewed published evidence on diagnostic performance and cost-effectiveness support a strategy of CTCA as a rule out (gatekeeper) test of CAD in low- to intermediate-risk patients since it has excellent diagnostic performance and as initial imaging test is cost-effective under different willingness-to-pay thresholds. More cost-effectiveness research is needed in order to define the role and choice of cardiac stress imaging tests.

To determine and compare the prognostic value of cardiac computed tomographic (CT) angiography, coronary calcium scoring, and exercise electrocardiography (ECG) in patients with chest pain who are suspected of having coronary artery disease (CAD). This study complied with the Declaration of Helsinki, and the local ethics committee approved the study. Patients (n = 471) without known CAD underwent exercise ECG and dual-source CT at a rapid assessment outpatient chest pain clinic. Coronary calcification and the presence of 50% or greater coronary stenosis (in one or more vessels) were assessed with CT. Exercise ECG results were classified as normal, ischemic, or nondiagnostic. The primary outcome was a major adverse cardiac event (MACE), defined as cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization and revascularization beyond 6 months. Univariable and multivariable Cox regression analysis was used to determine the prognostic values, while clinical impact was assessed with the net reclassification improvement metric. Follow-up was completed for 424 (90%) patients; the mean duration of follow-up was 2.6 years. A total of 44 MACEs occurred in 30 patients. Four of the MACEs were cardiac deaths and six were nonfatal myocardial infarctions. The presence of coronary calcification (hazard ratio [HR], 8.22 [95% confidence interval {CI}: 1.96, 34.51]), obstructive CAD (HR, 6.22 [95% CI: 2.77, 13.99]), and nondiagnostic stress test results (HR, 3.00 [95% CI: 1.26, 7.14]) were univariable predictors of MACEs. In the multivariable model, CT angiography findings (HR, 5.0 [95% CI: 1.7, 14.5]) and nondiagnostic exercise ECG results (HR, 2.9 [95% CI: 1.2, 7.0]) remained independent predictors of MACEs. CT angiography findings showed incremental value beyond clinical predictors and stress testing (global χ(2), 37.7 vs 13.7; P < .001), whereas coronary calcium scores did not have further incremental value (global χ(2), 38.2 vs 37.7; P = .40). CT angiography findings are a strong predictor of future adverse events, showing incremental value over clinical predictors, stress testing, and coronary calcium scores. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11110744/-/DC1.