Radiology: CCTA results stack up well vs. cardiac cath

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3D CCTA - 556.59 Kb
Images in 54-year-old man with atypical chest pain.Contrast–enhanced ECG-synchronized CCTA obtained after SPECT and displayed as 3D volume-rendered image. Source: Radiology (doi: 10.1148/radiol.12112426)

In patients with suspected coronary artery disease (CAD), coronary CT angiography (CCTA) can effectively differentiate patients who require revascularization from those who don’t, further supporting the modality’s potential as a noninvasive alternative to conventional cardiac catheterization, according to a study published online Aug. 8 in Radiology.

Therapeutic strategies chosen based on CCTA information were also in line with those based on cardiac catheterization, according to Antonio Moscariello, MD, of Medical University of South Carolina in Charleston, and colleagues.

“Coronary CT angiography has the potential to limit the number of patients without obstructive coronary artery disease who undergo conventional cardiac catheterization and to inform decision making with regard to revascularization,” wrote the authors.

A total of 185 consecutive symptomatic patients were included in the study, 121 of whom were men. All patients had a positive SPECT myocardial perfusion study and underwent both CCTA and conventional cardiac catheterization, which was used as the standard of reference. Conservative treatment or revascularization was chosen prospectively as the management strategy. Revascularization was accomplished either through percutaneous coronary intervention or coronary artery bypass graft surgery.

Results showed that 61 percent did not undergo revascularization and 23 percent were free of CAD, according to the authors. The same therapeutic strategy was chosen with CCTA as with catheterization in 96 percent of cases, and in cases where revascularization was indicated, the same procedure was chosen for 92 percent of patients.  

“The performance parameters of coronary CT angiography in this study, with a per-patient sensitivity and specificity of 100 percent and 93.6 percent, respectively, are consistent with the results of previous investigations that have demonstrated the strong performance of coronary CT angiography as a noninvasive alternative to conventional cardiac catheterization for the detection and exclusion of obstructive CAD,” wrote Moscariello and colleagues.

The authors also noted that their findings confirmed the low specificity of abnormal SPECT myocardial perfusion studies, since 59 percent of patients referred for catheterization on the basis of SPECT results did not have obstructive CAD. This is somewhat lower than specificities reported in previous literature, but the authors explained this is likely due to the fact that the SPECT imaging in the current study was performed in multiple facilities with varying equipment and expertise. “Although this may be seen as a limitation of our study, it also reflects the realities of patient care in the United States, where patients with positive findings at noninvasive testing are only moderately more likely to have a flow-obstructing lesion than those who do not undergo any testing.”