Table 4:

Comparison of IVUS vs CCTA in ESS Environment: All CCTA; 256-slice vs 64-slice (categorical variables)

Metric	IVUS (n=686))	CCTA (n=686))
3-mm segment with min ESS < 1.0 Pa	Low ESS
All CCTA (n=686)	174 (25.4%)	134 (19.5%)
256-slice CCTA (n=334)	85 (25.4%)	65 (19.5%)
64-slice CCTA (n=352)	89 (25.3%)	69 (19.6%)
3-mm segment with avg ESS 1.0 – 2.5 Pa	Physiologic ESS
All CCTA (n=686)	349 (50.9%)	307 (44.8%)
256-slice CCTA (n=334)	187 (56.0%)	163 (44.8%)
64-slice CCTA (n=352)	162 (46.0%)	144 (40.9%)
3-mm segment with avg ESS 2.5 – 5.0 Pa	High ESS
All CCTA (n=686)	246 (35.9%)	262 (38.2%)
256-slice CCTA (n=334)	106 (31.7%)	133 (39.8%)
64-slice CCTA (n=352)	140 (39.8%)	129 (36.6%)
3-mm segment with avg ESS 5.0 – 7.0 Pa	Higher ESS
All CCTA (n=686)	39 (5.7%)	56 (8.2%)
256-slice CCTA (n=334)	16 (4.8%)	21 (6.3%)
64-slice CCTA (n=352)	23 (6.5%)	35 (9.9%)
3-mm segment with max ESS >7 Pa	Very High ESS
All CCTA (n=686)	19 (2.8%)	68 (9.9%)
256-slice CCTA (n=334)	9 (2.7%)	18 (5.4%)
64-slice CCTA (n=352)	10 (2.8%)	50 (14.2%)

Values are presented as n (%) for categorical variables, n= number of analyzed segments CCTA= coronary computed tomography angiography, IVUS=intravascular ultrasound, Min ESS= minimal endothelial shear stress measured over a continuous 90° arc segment on each 3-mm subsegment, Max ESS= maximal endothelial shear stress, Avg ESS=average endothelial shear stress measured over a continuous 90° arc segment on each 3-mm subsegment. Some samples may be part of more than 1 category. For example, a sample that may have a physiological average ESS value, can have a Min ESS value lower than physiological or max ESS value higher than physiological, and therefore can be counted in Physiological ESS, low min ESS and/or high max ESS categories.

Agreement for all CCTA, kappa=0.25, p<0.0001

Agreement for 256 slice, kappa=0.26, p<0.0001

Agreement for 64 slice, kappa=0.24, p<0.0001