Introduction:
Coronary CT angiography (CCTA) demonstrates improved performance for diagnosis of high-grade coronary stenoses, but may be affected by artifacts and overestimation of stenosis severity. Whether the addition of resting myocardial perfusion attenuation patterns subtended by stenosis seen on CCTA improves diagnostic performance has not been examined to date.
Methods:
We evaluated 127 patients (mean age 53.0, 54.3% male) who underwent CCTA and ICA. Percentage of coronary stenosis was assessed by quantitative coronary angiography (QCA), which served as the reference comparator to CCTA. CCTA stenosis was categorized as 0%, 1-24%, 25-49%, 50-69%, 70-99%, and 100% luminal diameter reduction. Automated software (SmartHeart, Redwood City, CA) was used to measure resting CT perfusion attenuation patterns in myocardial segments by AHA 17-segment model. Segmental CT attenuation values were assigned to territories subtended by left anterior descending (LAD), left circumflex (LCX), and right coronary arteries (RCA). Per-patient and per-vessel analyses were based on highest severity (maximal stenosis, minimal attenuation). On both per-patient and per-vessel basis, logistic regression was devised for CCTA stenosis alone and for CCTA plus resting myocardial attenuation. Diagnostic accuracy and area under the receiver operating characteristics curve (AUC) were determined.
Results:
Diagnostic accuracy of CCTA alone was 84.0%, 85.5%, 90.4%, and 88.6%, at per-patient, per-LAD, per-LCX and per-RCA level, respectively. In comparison, the accuracy of CCTA plus myocardial attenuation were 89.6%, 91.9%, 95.2%, and 92.7%. The AUCs using CCTA alone to discriminate QCA-confirmed coronary stenoses >70% were 0.823 (95% CI: 0.737-0.909), 0.782 (95% CI: 0.667-0.898), 0.690 (95% CI: 0.503-0.878), and 0.793 (95% CI: 0.640-0.945) for per-patient, per-LAD, per-LCX, and per-RCA analysis, respectively. The AUCs using CCTA plus myocardial attenuation improved to 0.864 (95% CI: 0.765-0.962), 0.881 (95% CI: 0.793-0.968), 0.772 (95% CI: 0.535-1.000), and 0.820 (95% CI: 0.685-0.954).
Conclusions:
The addition of resting CT myocardial perfusion attenuation patterns improves identification and discrimination of high-grade coronary stenosis by CCTA.
Comparison of the Diagnostic Performance of Four Quantitative Myocardial Perfusion Estimation Methods Used in Cardiac MR Imaging: CE-MARC Substudy
