OBJECTIVE
To assess the dynamics of coronary atherosclerotic plaques (ASP) in patients with acute coronary syndrome (ACS).
MATERIAL AND METHODS
This study included 40 patients aged 61.9±11 years with ACS after percutaneous coronary intervention (PCI) for culprit lesions. All patients underwent coronary CT angiography (CTA) (320-row CT scanner) in 3—6 days after clinical manifestation, repeated scanning — after 17±6.2 months. We analyzed stenosis degree, morphological features, as well as well-known signs of ASP instability (napkin-ring sign, positive remodeling of the artery, spotty calcifications, rough contour).
RESULTS
There were 68 (66.7%) soft and 34 (33.3%) combined ASPs. Only 4 (3.9%) plaques have been changed from soft to combined ones. By the end of the follow-up period, the following ASP characteristics progressed: degree of stenosis from 58.3±16.3 to 60.4±16.1% (p=0.049), plaque burden from 74.2±11.1 to 75.9±11.2%, (p=0.043), plaque length from 10.0 [7.2; 14.0] mm by 0.25 [0.00; 1.00] mm (p=0.008). Mean and minimal plaque density and remodeling index were 64.0 [56.0; 71.0] HU, 30.0 [21.5; 38.5] HU and 1.3 [1.2; 1.49], respectively. There were no significant changes in these signs. The strongest correlation was observed between plaque burden and degree of stenosis (rho=0.611, p<0.001), mean and minimal plaque density (rho=0.8, p<0.001). Baseline incidence of various CT signs of instability in non-culprit plaques was 17—45%. Subsequent appearance or disappearance of at least one of these signs was observed in 24 plaques (24.2%). We found the relationship between appearance of positive remodeling and napkin-ring sign (U=0.236, p<0.001), as well as between disappearance of rough contour and positive remodeling (U=0.102, p=0.008).
CONCLUSION
Mean-group significant increase in degree of coronary artery stenosis, length and plaque burden was shown throughout the follow-up period. In ACS after PCI for culprit lesions, various CT signs of plaque instability are common (17—45%). In the future, appearance or disappearance of at least one of them is noted in a quarter of plaques. Significant relationships between appearance or disappearance of pairs of instability signs reflect the processes of plaque «destabilization» and «stabilization». Our data confirmed the capabilities of CTA for evaluation of structural features and instability of ASP remaining after PCI for culprit lesions.
