Abstract 11001: Prognostic Value of Evaluation of Plaque Characteristics Using Coronary CT Angiography in Patients With Unknown Coronary Artery Disease
Background: Coronary CT angiographic (CTA) findings of positive vessel remodeling (index>1.1) and low-attenuation (<30HU) plaque represent features of CT-verified high-risk plaques (CT-HRP). We examined the prognostic value of evaluation of plaque characteristics using CTA in patients with unknown coronary artery disease (CAD).
Methods: Between September 30, 2008 and April 30, 2011, 1572 consecutive patients with unknown CAD (ages: 35-74 yrs) underwent CTA and coronary artery calcium score (CACS). Patients who underwent PCI or CABG within 30 days after CTA and patients with no plaques and/or calcification were excluded. Of the remaining 739 patients, clinical follow-up (701.2±259 days) data could be obtained in 628 (85%) subjects and were enrolled. Age, gender, hypertension, diabetes, dyslipidemia, smoking, CACS, CHD 10-year-risk, the presence of CT-HRP and the number of vessel disease were investigated as predictors for cardiac event, including cardiac death, acute myocardial infarction and hospitalization for unstable or progressive angina.
Results: During the follow-up period, 26 cardiac events occurred. Kaplan-Meyer estimates showed that the probability of cardiac event increased significantly for male (log rank: p= 0.021), diabetes (p= 0.012), CACS (p= 0.002) and CT-HRP (p<0.0001). However, the probability of a cardiac event did not significantly increase with CHD 10-year-risk (p=0.067) in this population. Multivariate analysis using cox proportional hazard model revealed that CT-HRP (OR: 5.79, 95%CI: 2.1861-15.3599, P=0.0004), CACS 101-400 (11.80, 1.5036-92.6219, P=0.0195) and CACS>400 (18.2670, 2.1286-156.7623, P=0.0084) were significant predictors for a cardiac event.
Conclusions: Although cardiac event rate was low, approximately 15% of patients with CT-HRP and 27% of patients with CT-HRP and CACS>100 developed cardiac events within 1year. Evaluation of plaque characteristics and CACS should be performed if CTA is undertaken for the detection of CAD.
- © 2013 by American Heart Association, Inc.