Abstract 2003: The Characteristics of Non-Culprit Coronary Plaques in Patients with Acute Coronary Syndrome: Noninvasive Assessment by 64-Slice Computed Tomography
Some invasive imaging modalities such as intravascular ultrasound and angioscopy have shown the vulnerability of non-culprit plaques in patients with acute coronary syndrome (ACS). Recently multi-slice CT (MSCT) has been used to assess the characteristics of coronary plaque and the major advantage of MSCT is that it can evaluate all coronary plaques noninvasively. The purposes of this study are to assess coronary plaques noninvasively by MSCT and compare the differences of plaque composition between culprit and non-culprit lesions in patients with ACS and stable lesions in the patients with stable angina pectoris (SAP). 64-slice CT was performed in 27 patients with ACS and 33 patients with SAP before percutaneous coronary intervention. According to CT value, we defined plaque components as soft plaque (SP <50 HU), fibrous plaque (50 HU <FP <150 HU) and calcified plaque (CP >500 HU). In all obstructive lesions, we evaluated plaque characteristics by calculating the volume of SP, FP and CP. On the basis of clinical presentation, electrocardiogram and angiographic appearance, coronary lesions in the patients with ACS are divided into culprit or non-culprit lesions. Coronary lesions in the patients with SAP are defined as stable lesions. We analyzed 89 lesions with excellent image quality. Culprit lesions (n=19) and non-culprit lesions (n=25) had significantly larger volumetric percentage of SP and higher remodeling index compared to stable lesions (n=40) (34.4% vs. 29.3% vs. 21.0%, p<0.0001 and 1.061 vs. 1.061 vs. 0.971, p=0.01, respectively). But there was no significant difference in plaque composition between culprit lesions and non-culprit lesions. We assessed coronary plaques noninvasively by MSCT and found that non-culprit lesions in the patients with ACS, as well as culprit lesions, had significantly larger volumetric percentage of SP and higher remodeling index compared to stable lesions in the patients with SAP, supporting the concept of multiple vulnerable plaques in patients with ACS.