Abstract

Background: Fibrinogen-to-albumin ratio (FAR) has been proposed as a readily available inflammatory biomarker associated with coronary artery disease (CAD). However, its association with CAD severity and prognosis has predominantly been assessed in patients with acute coronary syndromes (ACS). The Leiden score is a validated comprehensive measure of CAD incorporating stenosis proximity, severity, and plaque type that independently predicts cardiovascular events. Whether FAR is associated with Leiden score or high-risk plaque features on coronary computed tomographic angiography (CCTA) in stable outpatients is unknown. Methods: Adult outpatients undergoing clinically indicated CCTA were enrolled (5/2021-9/2023) in a prospective study assessing the relationship of plaque to immune markers and provided same-day pre-scan peripheral venous blood samples. CCTAs were post-processed and analyzed by the consensus of two expert readers blinded to clinical data using a 17-segment model to determine coronary artery calcium (CAC), Leiden score, and high-risk plaque features. Patients were grouped by FAR (quartiles), Leiden score (<5, 5-20, >20), and CAC score (0, >0-100, >100-300, >300-1000, >1000). Numerical variables were compared via Wilcoxon and Kruskal-Willis tests. Spearman correlation was calculated between FAR and Leiden score. Results: Of 284 patients, 53.8% were male, 86.7% were white, and 58.8% were on a statin (Table 1). Median FAR was 70.3 mg/g, 64.0% had a non-zero CAC score, and 25.0% had at least one segment with one high-risk plaque feature. Across quartiles of FAR, there was no difference in Leiden score (5.8 (IQR: 0.0-18.5), 12.4 (3.1-20.7), 8.0 (0.0-19.9), 6.8 (0.0-21.1), p=0.50) or probability of having at least one segment with at least one (29.6%, 23.9%, 23.9%, 22.5%, p=0.69) or two (18.3%, 14.1%, 12.7%, 15.5%, p=0.66) high-risk plaque features. There was no correlation between FAR and Leiden score (R=0.03, p=0.66). There was no difference in FAR when stratified by Leiden score (Table 1, p=0.53), CAC score (Table 2, p=0.50), or number of segments with at least one high-risk plaque feature (Table 3, p=0.18). Conclusion: In a prospective cohort of adult outpatients across a wide spectrum of CAD burden with high rates of baseline statin use, FAR was not associated with CAD or presence of high-risk plaque features on CCTA. Further evaluation of its role as an inflammatory biomarker in larger populations, particularly patients without ACS, is required.