Abstract 14529: Long Term Prognosis Using Plaque Characteristics by Coronary Computed Tomography Angiography: A 9-Year Follow-Up of 3255 Patients

Abstract

Purpose: Coronary computed tomography angiography (CCTA) has a potential to predict acute coronary syndrome (ACS) with plaque characteristics of high risk plaque (HRP; positive remodeling and/or low attenuation). To clarify the feasibility of CCTA for a long term prediction of ACS, the relation between plaque characteristics and the period from CTA to the onset of ACS was evaluated.

Methods: A total of 3255 patients underwent CTA from March 2003 to January 2011 (follow-up: range 1-218, median 48 months). An event occurred in 291 (9.0%); 115 non-cardiac death, 30 cardiac death, 56 hospitalization due to heart failure, 90 ACS. Of 90 ACS, 24 restenotic lesions and 14 unknown culprit lesions were excluded. In the remaining 52 patients, the presence of HRP, luminal stenosis of more than 70%, and the period from CTA to ACS were evaluated.

Results: ACS was occurred in 22 HRP+ lesions and 30 HRP- lesions. The period from CTA to ACS was significantly shorted in HRP+ than HRP- lesions (10.8±7.6 vs 34.9±24.9 months, p<0.0001) (left figure). ACS occurred in 24 months after CTA at all 22 HRP+ lesions. In 30 HRP- lesions, all 5 lesions with ACS in 12 months had ≥70% stenosis. Eighteen lesions without HRP and ≥70% stenosis resulted in ACS after 12 months of CTA (lower table). Cut-off value of period from CCTA to ACS to predict ACS by HRP was 15 months by Receiver Operating Characteristic curve, and sensitivity and specificity were 77.3% and 80.0%, respectively (right figure).

Conclusions: Although the presence of HRP by CCTA was a predictor of ACS in 2 years, the absence of HPR could not deny the risk of ACS after 1 year of CCTA even in the lesions without significant lumen stenosis. Plaque assessment by CCTA had potential for short term risk stratification, however, CCTA had the limitation for a long term prediction of ACS.