Abstract 18899: Distribution of Low CT Number Area is Dominant and Wide in Vessel Containing Vulnerable Plaque - Vessel-wide Cross-sectional Scannning by Multi-detector Row Computed Tomography

Abstract

Introduction. Lipid-rich plaque is shown to be dominant in the culprit by intravascular ultrasound and multidetector row computed tomography in acute coronary syndrome (ACS) than in stable angina pectoris (SAP). However, there were few reports compared the disposition of lipid-rich plaque in vessel-wide.

Hypothesis We assessed the hypothesis that lipid-rich plaque is dominantly located in ACS patients by our original vessel-wide cross-sectional scanning.

Methods One hundred eight patients (32 acute coronary syndrome (ACS), 38 stable angina pectoris (SAP), and 38 patients without plaque) underwent 64-slice computed tomography angiography. Cross-sectional images for 1mm-intervals were analyzed containing culprit lesion from the ostium. Areas and ratio of 0-50, 50-100, 100-150, 150-200, 200-250, 250-300, 300-350, 350-400, 400-450, >450HU surrounding vessel were calculated for each cross-sectional images and continuously demonstrated as a graph (see figure).

Results Analyzed cross-sectional images were averaged 52±18 images for 76 vessels. Fifty cross-sectional images for 38 vessels in patients without plaque were analyzed as control. The ratios of 0-50, 50-100 HU were statistically dominant in ACS patients compared to SAP patients or without plaque (34.7±14.4% vs. 19.6±4.1% vs. 14.8±3.6%, P<0.0001; 22.3±5.5% vs.15.4±3.4% vs. 14.6±2.0%; P<0.0001). The number of slices in which 0-50HU were dominant were higher in ACS than SAP (18±6 vs 12±4 slices, p<0.01). The number of positive remodeling in the vessel was higher ACS than SAP (3.6±0.9 vs. 1.5±0.8, p<0.001). The slices of 64 culprits (91%) were not the most distributed by 0-50HU in the vessels.

Conclusions. In ACS patients, lipid-rich component, demonstrated as the area 0-50HU, distributed dominantly and wide on the vessel including the culprit.