CORONARY ARTERY CHARACTERISTICS BY VOLUME COMPUTED TOMOGRAPHY IN PATIENTS WITH ACUTE CORONARY SYNDROME
P urpose. To analyse the structure and to identify vulnerable plaque features in non-culprit coronary lesions in patients with ACS according to volumetric computer coronary angiography. Materials and methods. The study included 73 patients with acute coronary syndrome (59 men - 80.82% and 14 women - 19.18%), who underwent volumetric coronary computed tomography angiography (CCTA) with retrospective ECG gating and intravenous contrast enhancement. The study was carried out on an Aquilion ONE Vision Edition 640, Canon, Japan with 320 rows of detector elements and a detector width of 160 mm. The level of plaque stenosis, plaque length, plaque burden were assessed. Also the presence of vulnerable plaque features such as microcalcifications, low-density plaque area, remodeling index, napkin ring sign and plaque contour were analyzed. 63 patients underwent invasive coronary angiography (ICA) when clinically indicated. The results of CCTA and ICA were compared. Results. 236 plaques with a soft tissue component were included in the study. Structural analysis of plaques showed a predominance of soft ones - 161 (68.22%), against combined ones - 75 (31.78%) (p<0.05). According to volumetric CCTA, severe stenosis of 70-99% was detected in 17.65% of cases (n=39), moderate stenosis of 50-69% in 43.44% of cases (n=96), initial 25-49% and minimal 1-24% stenosis was detected in 33.48% (n=74) and 1.36% of cases (n=3), respectively. Atherosclerotic plaque had an average length of 12.66 ± 6.83. A positive remodeling index was found in 45 cases (19.07%), the mean plaque burden was 69.62 ± 11.09%. Microcalcifications were detected in 64 cases (27.12%), low attenuation plaque <46 HU - in 21 cases (8.90%), napkin-ring sign - in 19 cases (8.05%), and the irregular plaque contour was detected in 9 cases (3.81%). Half of non-culprit coronary plaques showed signs of vulnerability (122 plaques, 51.65%). Volumetric CCTA showed high accuracy, specificity and prognostic value of a negative result (95.9%, 97.9% and 97.4%), but lower sensitivity and prognostic value of a positive result (84.8% and 87.5%). Positive remodeling (IR>1.1) showed statistically significant discrepancy between CCTA and ICA in quantification of coronary arterial stenosis (p<0.05). Discussion. The results of the study confirm the theory of the multifocal nature of atherosclerotic plaques destabilization in patients with cardiovascular events. Atherosclerotic plaques with one or more signs of instability were detected on non-culprit coronary area. The data obtained are consistent with the results of other authors. Conclusion. Volumetric CCTA has a high diagnostic value, allows analysing not only the degree and volume of arterial stenosis, but also the qualitative plaque composition without using invasive diagnostic methods. The data resulting from the study show the importance of non-culprit lesion examination for identifying plaques with signs of instability and its further control.