Diagnostic Performance of Dynamic Myocardial Perfusion Imaging Using Third-Generation Dual-Source Computed Tomography in Patients with Intermediate Pretest Probability of Coronary Artery Disease

TL;DR

Combining two CT scans improves accuracy in detecting significant heart artery blockages compared to using one scan alone.

Contribution

Combining CCTA with dynamic CT-MPI improves diagnostic accuracy for hemodynamically significant CAD in intermediate-risk patients.

Findings

Combined CCTA and CT-MPI showed higher specificity and area under the ROC curve than CCTA alone.

The combined approach improved diagnostic performance for identifying hemodynamically significant coronary stenosis.

Median radiation dose for both scans was 8.05 mSv.

Abstract

(1) Background: Our aim was to evaluate the diagnostic performance of combined coronary computed tomography angiography (CCTA) and dynamic CT myocardial perfusion imaging (CT-MPI) for detecting hemodynamically significant coronary artery disease (CAD) in patients with intermediate pretest probability. (2) Methods: Patients with an intermediate pretest probability of CAD were retrospectively enrolled. All patients underwent CCTA and dynamic CT-MPI using a third-generation dual-source CT scanner prior to invasive coronary angiography (ICA). Anatomically significant stenosis was defined as ≥50% luminal narrowing on both CCTA and ICA. Fractional flow reserve (FFR) was performed during ICA in selected cases. Hemodynamically significant CAD was defined per vessel as FFR ≤ 0.80, angiographic stenosis ≥70%, or having undergone revascularization. The diagnostic performance of CCTA alone and CCTA combined with CT-MPI was compared against this reference standard. (3) Results: Seventy-four patients (mean age, 66.8 ± 11.1 years; 59 men) were included. The median coronary calcium score was 508.5 Agatston units (interquartile range: 147–1173). ICA and CCTA detected anatomically significant stenoses in 137 (61.7%) and 146 (65.8%) coronary vessels, respectively, and in 62 (83.8%) and 71 (95.9%) patients, respectively. Hemodynamically significant stenosis was present in 56 patients (76%) and 99 vessels (45%). On a per-vessel basis, CCTA alone yielded a sensitivity of 96.7%, specificity of 60.3%, positive predictive value (PPV) of 64.4%, and negative predictive value (NPV) of 96.1%. Combined CCTA and CT-MPI demonstrated a sensitivity of 90.1%, specificity of 84.3%, PPV of 82.7%, and NPV of 91.1%. The area under the receiver operating characteristic curve improved from 0.787 (95% confidence interval: 0.73–0.84) for CCTA to 0.872 (95% confidence interval: 0.82–0.91) for the combined approach (p < 0.05). The median total radiation dose for both CCTA and CT-MPI was 8.05 mSv (interquartile range: 6.71–11.0). (4) Conclusions: In patients with intermediate pretest probability of CAD, combining CCTA with dynamic CT-MPI significantly enhances the diagnostic performance for identifying hemodynamically significant coronary stenosis compared to CCTA alone.

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