[Computed Tomography in the Evaluation of Coronary Atherosclerotic Plaques: Comparison With Intravascular Ultrasound].

PURPOSE: Determination of computed tomography angiography (CTA) informativeness in assessment of state of atherosclerotic coronary plaque (ACP) and identification of signs of its instability compared with intravascular ultrasound (IVUS).

MATERIALS AND METHODS: Coronary CTA was carried out in 52 patients with clinical presentation of non-ST elevation (NSTE) acute coronary syndrome on the first day of hospitalization. ACPs were identified in 32 of 52 patients (61.5%). IVUS was performed in 32 patients (mean age 58+/-11.4 years, 27 men, 5 women, 22 with unstable angina, 10 with NSTE myocardial infarction) and 50 plaques in 45 coronary arteries were characterized (39 with spectral analysis of IVUS data). All data were compared with the results of coronary CTA.

RESULTS: Sensitivity and specificity of CTA in the detection of stenosis >50% were 97.67 and 71.40%, respectively. Correlation analysis showed a high comparability of methods in determining plaque burden (r=0.80, 95% confidence interval [CI] 0.67 - 0.88, p<0.0001), plaque length (r=0.75, 95%CI 0.60 - 0.85, p<0.0001), and remodeling index (r=0.62, 95%CI 0.40 - 0.77, p<0.0001). Threshold value for "low-density areas" of plaques typical for thin cap fibroatheroma was less or equal 41 Hounsfield units (sensitivity 82%; specificity 86%; area under the curve 0.824; 95% CI 0.615 - 0.947, p<0.0005).

CONCLUSION: Coronary CT is a non-invasive method for rapid characterization of ACP. CT results correlate well with IVUS data, including identification of such important signs of plaque instability as presence of "low-density zone" and positive remodeling at the plague level.