Abstract 1903: Noninvasive Assessment of the Coronary Plaque Characteristics in Culprit Lesion of Unstable Angina Pectoris by Multislice Computed Tomographic Coronary Angiography
Background: Intravascular ultrasound studies show that patients with unstable angina pectoris (UAP) more frequently have soft plaques in the culprit coronary artery compared with those with stable angina pectoris (SAP).
Purpose: We evaluated plaque characteristics of a culprit lesion in patients with UAP by multislice computed tomographic coronary angiography (MSCTA).
Methods: MSCTA (Aquillion 64, Toshiba Medical Systems, Japan) was performed in consecutive 30 patients with coronary artery disease (UAP=14, SAP=16) before percutaneous coronary intervention (PCI). Coronary plaque area was measured by manual tracing as the difference between the vessel area (inside area of the external elastic membrane) and the lumen area at the site of maximal lumen narrowing on cross-sectional MSCTA images where PCI was performed. In this plaque area, low density plaque area (a mean CT density less than 50 Hounsfield units) was automatically traced and measured.
Results: As shown in table⇓, although there was no difference of culprit plaque area between UAP and SAP, low density plaque area was significantly greater in UAP than SAP. Serum levels of high-sensitivity C-reactive protein (hsCRP) are 2.3mg/L in UAP patients and 0.7mg/L in SAP patients (p=0.006).
Conclusion: On noninvasive MSCTA images, greater area of low density plaque in the culprit coronary lesion and elevated hsCRP are associated with UAP rather than SAP.