[Association between pericoronary fat attenuation index and high-risk plaques in patients with FFR-negative acute...

Objective: To investigate the relationship between fat attenuation index (FAI) measured by coronary computed tomography angiography (CCTA) and high-risk plaques in patients with acute coronary syndrome (ACS) and negative fractional flow reserve (FFR). Methods: This single-center cross-sectional study enrolled a total of 342 consecutive patients with a confirmed diagnosis of ACS, who underwent coronary angiography and had negative FFR results (>0.80) at the Department of Cardiology, General Hospital of Northern Theater Command, from January 2016 to December 2022. All patients underwent CCTA within 1 month before the onset of ACS. According to the CCTA findings of the target vessels, patients were divided into a high-risk plaque group (n=165) and a non-high-risk plaque group (n=177). Semi-automated software was used to evaluate the FAI centered on the culprit lesion. The FAI values were compared between the two groups. A multivariate logistic regression model was applied to explore the association between high-risk plaques and FAI. The diagnostic performance of the model was assessed using receiver operating characteristic curve analysis. Results: The age of the patients was (64 (53, 78)) years, and there were 178 (52.0%) males. The FAI value was significantly higher in the high-risk plaque group than in the non-high-risk plaque group ((-79.79±9.10) HU vs. (-84.21±10.14) HU, P=0.001). Multivariate logistic regression analysis revealed that FAI was independently associated with high-risk plaques (OR=1.056, 95%CI 1.022-1.092, P=0.001). The receiver operating characteristic curve showed that the area under the curve of FAI for diagnosing CCTA high-risk plaques was 0.748, with a sensitivity of 64.4% and a specificity of 73.8%, and the optimal cutoff value of FAI for identifying CCTA high-risk plaques was -80.5 HU. Conclusion: The FAI measured by CCTA is independently associated with high-risk plaques in ACS patients with negative FFR.