Table 4.

Comparison of discriminatory capacity of quantitative high-risk plaque measurements using IVUS based thresholds and newly derived coronary CTA based thresholds (maximized for AUC) for diagnosis of ACS in patients with coronary plaque (n=255).

	AUC* (95%CI)	p value	NRI (95%CI)**	p value
IVUS based measures
Remodeling index
>1.05	0.630 (0.570-0.690)	0.402	0.064 (−0.100-0.227)	0.447
>1.10	0.624 (0.548-0.700)	0.187	0.077 (−0.042-0.196)	0.207
>1.17	0.662 (0.577-0.747)
Minimal luminal area
≤4mm2	0.742 (0.689-0.796)	0.066	0.149 (−0.032-0.330)	0.106
≤1.43mm2	0.817 (0.736-0.898)
Plaque burden
≥70%	0.676 (0.591-0.762)	<0.001	0.312 (0.060-0.563)	0.015
≥55%	0.832 (0.768-0.896)
TCFA equivalent – Low HU plaque volume <30 HU (mm3)
≥1.31 mm3	0.725 (0.646-0.804)
Other measures
Diameter stenosis
≥50%	0.824 (0.741-0.906)	0.317	0.004 (−0.004-0.013)	0.317
≥70%	0.721 (0.632-0.810)	0.005	0.210 (0.047-0.372)	0.011
≥52%	0.826 (0.743-0.908)
Lesion length
≥11.2mm	0.798 (0.739-0.858)	0.450
≥13.09mm	0.817 (0.747-0.886)

IVUS = Intravascular Ultrasound;

^*AUC = area under the curve (in respect to the dichotomized threshold); 95%CI = 95% confidence interval; Remodeling index (calculated as the ratio of the outer vessel wall area at the site of the minimal luminal area and the vessel area defined by the vessel wall reference at that location); Plaque burden (plaque area in % of the total vessel area derived from a cross-sectional view); TCFA = thin cap fibroatheroma; HU = Hounsfield Units; Lesion length (calculated as the centerline distance from the proximal to distal end of the plaque.

^**Improvement of coronary CTA derived thresholds compared to IVUS derived thresholds for the prediction of ACS