Abstract Body (Do not enter title and authors here): Introduction. Improving the risk stratification of cardiovascular events based on the analysis of structural changes in the coronary arteries in patients (pts) with ACS is relevant and significant.
Purpose. Development of a "Risk Score Scale" ("RSS") of MACE based on computed tomographic angiography (CTA) data for pts with ACS.
Methods. The study included 249 pts with ACS (77.5% men, age 58.2 ±10.7 years). Unstable angina occurred in 26.5% of pts, MI – in 73.5%. PCI for culprit lesions was performed in 90% of pts. On the 3rd-7th day of hospitalization CTA was performed by 64 - row CT scanner in 16% of pts and 320 - row CT scanner in others. The characteristics of 785 plaques were determined in pts, including 609 uncalcified ones. We assessed coronary obstruction, morphology and signs of uncalcified plaques instability, such as the presence of low-attenuation area <30 HU, napkin-ring sign, positive remodeling, spotty calcifications, rough contour. The total number of plaques and the number of plaques with certain characteristics were also evaluated.
Results. During 39.1 [18.0;57.4] months of follow-up, 71 (28.5%) pts had MACE (at least one of the following events: nonfatal MI, unstable angina, cardiac death, unplanned PCI, ischemic stroke). In the univariate Cox analysis a significant association with the MACE was found in 14 out of 30 CTA characteristics. Multifactorial Cox analysis showed that 11 of the 14 predictors are independent of known clinical risk factors. ROC analysis of significant univariate CT predictors was used to develop the “RSS”. The uncensored period was 305 days. 26 MACE emerged during this period.
For each of the significant predictors, the cut-off values were calculated using the Yuden method, as well as corresponding AUC, Sn, Sp, PPV and NPV. The "RSS" includes 8 most optimal predictors. Their values of the points awarded are proportional to the values of their AUCs (Table).
For the resulting "RSS" the threshold value calculated by the Yuden method was 3 points. A score of >3 points indicates a high risk of MACE: odds ratio = 7.2, 95% CI: 2.6-19.7, p<0.0001. The AUC of the scale was 0.77 (Figure), Sn = 0.81, Sp = 0.63, PPV = 0.21, NPV = 0.97.
Conclusion. The use of “RSS” based on CTA characteristics is a new and practically significant technique that makes it possible to improve the risk stratification of adverse outcomes in the first year after ACS.