Abstract 11810: Coexistence of Three Vulnerable Plaque Characteristic Factors in Non Calcified Coronary Plaques was Greater Risk Predictor for Major Cardiac Events on CT Following a Median of 82 Months Using Kaplan-Meier Analysis

Abstract

Purpose: To evaluate influence of coexistence of three vulnerable plaque characteristics (VPC), in non calcified coronary plaques (NCP) with 1) low attenuation (LA) (<30HU), 2) positive remodeling (PR) and 3) focal calcification (FC) on CT for risk of major adverse cardiac events (MACE) using Kaplan Meier analysis (KMA) and a Cox proportional hazard model (CPHM).

Materials and Methods: A total of 325 consecutive subjects with suspected coronary artery disease (167 male; 64±12 yrs; hypertension, 60%; diabetes mellitus, 20%; dyslipidemia, 40%; smokers, 31%; and obese, 30%) with normal myocardium underwent CT (Light speed Ultra 16) from 2003 to 2004. Subjects were followed for a median of 82 months after CT and the incidence of MACE was compared. Subjects with old myocardial infarction or myocardial diseases were excluded from this analysis. MACE included cardiac death, acute coronary syndromes, new onset of angina pectoris, and cardiac failure.

Results: 96 subjects had NCP, (11 with LA, 48 with PR, and 34 with FC) and were classified into four groups, 1) 267 subjects with zero VPC, 2) 26 with one VPC, 3) 27 with two VPCs and 4) 5 with three VPCs. 7 subjects had a MACE. Subjects with three VPCs had a higher risk of MACE than any other group (all p<0.05) during the observation period. Significant differences between the subjects with three VPC and all other groups were observed at each time point when the whole follow up period was compared by KMA and log rank test (p<0.001). A CPHM revealed that coexistence of three VPCs on coronary arteries on CT was a greater predictor of MACE (Hazard ratio 14.9, 95% CI 1.8-119.4, p=0.01) in comparison with others.

Conclusions: Coexistence of three VPCs in coronary arteries on CT was a critical factor for prediction of MACE in subjects with normal myocardium on following for a median of 82 months. Even in asymptomatic subjects, if there would be three VPCs observed on CT, careful follow up with control of risk factors is desired.