Abstract 9205: CT Angiography-Based Coronary Risk Stratification in Subjects Presenting with No or Atypical Symptoms
Backgrounds: Coronary CT angiographic (CTA) findings of positive vessel remodeling (PR, index>1.1) and low-attenuation plaque (LAP, <30HU) referred to as 2-feature-positive plaques (2FPP) have been reported to be associated with development of subsequent acute coronary syndromes. Such angiographic observations coupled with recent technological advances in CT technology to reduce the dose of contrast medium and radiation exposure, may allow extension of indications for CTA for risk stratification in patients with asymptomatic and atypical chest symptom.
Methods: 1139 subjects (M:F=602:537, ages 30-74, 61.5±9.3 yrs) either asymptomatic or presenting with atypical chest symptom underwent coronary 64 or 320-slice MDCT angiography and coronary artery calcium scoring (CACS). Age, gender, coronary risk factors, including hypertension (HT), diabetes (DM), hyperlipidemia (HL), smoking, and and CACS were investigated as predictors for 2FPP by multivariable analysis using logistic regression analysis.
Results: 2FPP were observed in 72 patients (6.3%). Based on the Framingham Risk Score (FRS) assignments, 2FPP were observed in 0/94 (0.0%) in low, 35/806 (4.3%) in intermediate, and 3/239 (15.5%) in high risk group subjects. Logistic regression analysis revealed significant predictor for 2FPP to be a male (OR: 2.6, 95%CI 1.4-34.9, p=0.004), DM (2.4, 1.4-4.0, p=0.001), smoking (2, 1.1-3. 4, p=0.02), CACS 1-500 (2.3, 1.3-4.2, p=0.007) in intermediate and high risk group subjects. 2FPP were observed in CACS categories as follows:Risk Group CACS 0 CACS 1-500 CACS>500Intermediate 14/430 (3.3%) 19/345 (5.5%) 2/31 (6.5%)High 4/57 (7.0%) 29/150 (19.3%) 4/32 (12.5%)
Conclusions: In asymptomatic subjects and those presenting with atypical chest pain in intermediate-risk group, CTCA is contributory to FRS. In patients with high FRS risk, 2FPP prevalence in CACS>500 was lower. Male gender, DM, smoking and CACS 1-500 were independent predictors of the presence of vulnerable plaques in more than intermediate-risk group.
- © 2011 by American Heart Association, Inc.