Perivascular fat attenuation index on coronary computed tomography angiography predicts postoperative atrial fibrillation after off-pump coronary artery bypass grafting

Postoperative atrial fibrillation (POAF) is a prevalent complication following cardiac surgery, which has been associated with inflammatory activity in epicardial adipose tissue. There is a lack of effective means for its prediction and prevention. The fat attenuation index (FAI) serves as a non-invasive imaging biomarker capable of quantifying pericoronary adipose tissue inflammation. In this retrospective study, patients who underwent off-pump coronary artery bypass grafting (OPCABG) and had preoperative coronary computed tomography angiography (CCTA) were included. The pericoronary FAI was measured from CCTA images. POAF was identified based on ECG monitoring within 7 days after surgery. A multivariate logistic regression model incorporating variables significant in univariate analysis and clinically relevant factors was constructed. Model performance with and without FAI was compared using the area under the curve (AUC) with DeLong’s test. A total of 140 patients were finally included, including 41 patients (29.2%) in the POAF group and 99 patients (70.8%) in the NO-POAF group Multivariate logistic regression identified hypertension and a higher FAI around the right coronary artery as independent predictors of POAF, while history of myocardial infarction showed a trend toward significance. The inclusion of FAI (RCA) significantly improved model discrimination (AUC increased from 0.711 for the clinical model to 0.752; DeLong p = 0.049). The pericoronary FAI, particularly around the RCA, provides incremental predictive information and may help identify patients at elevated POAF risk; however, its precise clinical utility requires further validation. Perivascular fat attenuation index on coronary computed tomography angiography predicts postoperative atrial fibrillation after off‑pump coronary artery bypass grafting. FAI = fat attenuation index; RCA = right coronary artery; POAF = postoperative atrial fibrillation; OPCABG = off‑pump coronary artery bypass grafting