Perivascular fat attenuation index (FAI) on computed tomography coronary angiography reclassifies individual cardiovascular risk estimation

Background: The perivascular fat attenuation index (FAI) detects and quantifies coronary inflammation by measuring phenotypic changes in perivascular adipose tissue by using computed tomography coronary angiography images. Aim: The primary objective of this study was to evaluate the reclassification of cardiovascular (CV) risk after incorporating perivascular FAI assessment in currently used risk score algorithms. Methods: This was a single-center, retrospective study of 200 patients with suspected coronary artery disease who underwent computed tomography coronary angiography in clinical practice between January 2022 and May 2022. From the patients who met the inclusion criteria, we included 50 patients with the highest CV risk according to the U-prevent calculator score to perform the perivascular FAI analysis. High perivascular FAI was defined as either a FAI-Score of >= 75th percentile in the left anterior descending artery or right coronary artery, or >= 95th percentile in the left circumflex artery. Results: In 62 % of the patients, there was a reclassification in CV risk after perivascular FAI assessment; individual risk was upgraded in 22 % of patients and in 40 % their risk was downgraded. The presence of any plaque (72.7 % vs. 94.1 %; P = 0.032) and the proportion of patients with moderate-to-high coronary artery calcium score (>= 100 Agatston units) was higher in the high perivascular FAI group compared to the low FAI group (76.5 % vs. 36.4 %; P = 0.016). Major adverse cardiac and cerebrovascular events did not differ between both groups. Conclusion: The findings in this study suggest the potential valuable role of perivascular FAI assessment in individual CV risk prediction for patients with documented or suspected coronary artery disease.