Impact of coronary atherosclerotic plaque metrics and CT reader skills on inter-observer variation of repeated on-site CT-FFR

Abstract Funding Acknowledgements Type of funding sources: None. Background and Purpose Little is known about the on-site CT-FFR inter-reader reproducibility its variability in different atherosclerotic plaque scenarios. The aim this study was to determine variation repeated analyses between two CCTA readers with training skills across features. Methods Patients referred for invasive coronary angiography who accepted undergo a CCTA/CT-FFR were prospectively included. contraindications CCTA, atrial fibrillation, chronic total occlusions or previous revascularization excluded. Quantification metrics performed each vessel by CT readers, one Level I III. Inter-reader agreement assessed using kappa index, Bland-Altman Lin’s concordance correlation (LCCA). impact feature dividing dataset based on corresponding median assessing both lower upper half. Results 47 patients (137 vessels) Mean age 66 ± 10 years, 89% males, 63% had hypertension, 76% dyslipidemia 38% diabetes. Degree stenosis moderate (50-69%) 29% severe (≥70%) 28% vessels positive (≤0.80) 39%. showed good index 0.77 mean difference -0.017 0.12. main epicardial (LCCA 0.70 LAD, 0.74 LCX 0.76 RCA, p < 0.001 all) better proximal than distal segments 0.83 vs 0.63, 0.001). Likewise, scenarios, those volume, less calcified longer lesions (see table 1). Conclusions In our cohort, without relevant reader experience level Table 1 coefficient value Plaque volume (556 mm3) -0.01 0.12 0.85 <0.001 > -0.035 0.13 0.64 Calcified burden (34%) -0.03 0.11 0.82 -0.02 0.14 0.75 Lesion length (55 mm) -0.005 0.68 -0.031 *p values indicate independent observers category