RESUMO
Purpose To observe the characteristics of coronary artery lesion in patients with unstable angina pectoris (UAP) and stable angina pectoris (SAP) using virtual histology intravascular ultrasound (IVUS-VH).Materials and Methods A total of 199 patients with angina pectoris were enrolled and divided into SAP group (101 cases) and UAP group (98 cases) according to clinical symptoms, ECG and myocardial enzyme level. All the patients underwent coronary angiography to determine the criminals vessels, grayscale intravascular ultrasound was used to measure and compare the external elastic membrane area (EEMA), lumen cross-sectional area (lumen CSA), plaque area (PA), plaque burden (PB), remodeling index (RI), plaque eccentricity index (EI) of the criminals vessels. IVUS-VH method was used to measure and compare the area and percentage of calcified tissue,fibrous tissue, lipid tissue and necrotic tissue in the plague components of the criminals vessels between the two groups.Results There was no significant difference (t=1.392,-0.345, 1.921, 0.378 and 0.857,P>0.05) of EEMA, lumen CSA, PA, EI and RI measured at the location with smallest lumen area between the two groups. Necrotic core area and percentage of lesion composition in UAP group was significantly higher than that in SAP group (t=2.361,P0.05) between the two groups on the area of fiber, lipid and calcification. On the distribution of plaque components, fibrous plaque area percentage of UAP group was lower than that in SAP group (t=-2.418, P0.05) between the two groups on lipid and calcification area.Conclusion Necrotic core area and percentage of plaque composition in the UAP group is larger than the other group. Criminals lesions are more unstable and more easily to be complicated with acute cardiovascular events.