Abstract 18957: Plaque Vulnerability Assessment by Coronary Artery Remodeling Using 320-Slice Computed Tomography Angiography
Purpose: Culprit plaques resulting in acute coronary syndromes are usually large and demonstrate low attenuation (LAP) and positive remodeling (PR) on CT angiography (CTA). When identified in non-ACS subjects, such plaques with one or both characteristics (1- or 2-FPP) determine plaque vulnerability to rupture; 2FPP are associated with more than 22 percent likelihood of development of an acute event over the next 2 years. We hypothesized that the extent of vascular remodeling would be greater in culprit 1- or 2-FPP compared to non-culprit 1- or 2-FPP plaques.
Methods: 491 consecutive patients underwent 320-slice CTA; all plaques were characterized for the presence of PR and LAP. The remodeling index was measured in area and compared between ACS culprit and non-culprit 1- or 2-FPP lesions in ACS and 1- or 2-FPP lesions in non-ACS patients. Cut-off value to detect the ACS-related lesions was determined by ROC curve.
Results: Plaque analysis was performed in 5976 vascular segments in 491 patients; 116 segments in 90 patients revealed ACS culprit or 1- or 2-FPP lesions. Of 39 ACS patients, culprit lesions were identified in 37 segments of 37 patients, and 18 patients showed additional 21 segments with 1- or 2-FPP lesions. 51 of 90 patients with no ACS also revealed 58 segments with 1- or 2-FPP lesions. Culprit lesions showed RI of 1.45±0.24, which was significantly greater than non-culprit 1- or 2-FPP lesions in ACS (1.27±0.21, p=0.007) or non-ACS (1.33±0.28, p=0.002) patients. The cut-off value of RI to predict ACS was 1.35 based on ROC curve; sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy was 73%, 67%, 51%, 84%, and 69%, respectively.
Conclusions: There is a significant expansion of the plaque PR before the rupture. It is conceivable that although PR is one important determinant of plaque vulnerability, it alone may not offer sufficient independent discriminatory ability for the prediction of ACS.
- © 2010 by American Heart Association, Inc.