Establishing the diagnosis of coronary artery disease (CAD) in symptomatic patients allows appropriately allocating preventative measures. Nuclear myocardial perfusion imaging (SPECT-MPI) is frequently utilized for the evaluation of CAD but coronary CT angiography (CTA) has emerged as a valid alternative.
We compared the accuracy of SPECT-MPI and CTA for the diagnosis of CAD in 391 symptomatic patients who were prospectively enrolled in a multicenter study after clinical referral for cardiac catheterization. Area under the receiver-operating-characteristic curve (AUC) was used to evaluate the diagnostic accuracy of CTA and SPECT-MPI for identifying patients with CAD defined as presence of ≥1 coronary artery with ≥50% lumen stenosis by quantitative coronary angiography.
Sensitivity to identify patients with CAD was greater for CTA than SPECT-MPI (0.92 vs. 0.62, respectively, p<0.001), resulting in greater overall accuracy (AUC 0.91 [95% confidence interval 0.88–0.94]) vs. (0.69 [0.64–0.74], p< 0.001). Results were similar in patients without prior history of CAD (AUC 0.92 [0.89–0.96] vs. 0.67 [0.61–0.73], p< 0.001), and also for the secondary endpoints of ≥70% stenosis and multivessel disease, as well as subgroups, except for patients with calcium score ≥400 and those with ‘high risk’ anatomy in whom overall accuracy was similar because CTA’s superior sensitivity was offset by lower specificity in these settings. Radiation doses were 3.9 mSv for CTA and 9.8 for SPECT-MPI (p<0.001).
CT angiography is more accurate than SPECT-MPI for the diagnosis of CAD as defined by conventional angiography and may be underutilized for this purpose in symptomatic patients.
URL: http://www.clinicaltrials.gov. Unique identifier: [Related object:]NCT00934037.