Predictive Value of Uric Acid-to-Albumin Ratio for Left Atrial Thrombus or Spontaneous Echo Contrast in Patients with Non-Valvular Atrial Fibrillation

Background: The uric acid-to-albumin ratio (UAR) is a novel inflammatory marker linked to cardiovascular disease. This study aimed to evaluate the predictive value of UAR for left atrial thrombus or spontaneous echo contrast (LAT/SEC) in non-valvular atrial fibrillation (NVAF), explore its mediating mechanisms, and assess the incremental value beyond the CHA 2 DS 2 -VASc score. Methods: This retrospective study included 514 patients with NVAF undergoing transesophageal echocardiography (TEE). Multivariable logistic regression, restricted cubic splines (RCS), generalized additive models (GAMs), receiver operating characteristic (ROC) curves, and mediation analyses were employed to evaluate the relationship between UAR and LAT/SEC. Reclassification indices assessed UAR’s incremental value beyond the CHA 2 DS 2 -VASc score. Results: The prevalence of LAT/SEC was 17.32%. UAR was independently associated with LAT/SEC (OR: 1.43, 95% CI: 1.25– 1.66; P < 0.001) in a nonlinear manner ( P for non-linearity = 0.031). A threshold effect was identified at 12.11, below which the risk increased more significantly (OR: 1.61, 95% CI: 1.36– 1.92; P < 0.001). UAR showed better predictive performance (AUC=0.712) than UA (0.684) and albumin (0.612). Incorporating UAR into the CHA 2 DS 2 -VASc model improved risk stratification. Mediation analysis indicated that left atrial diameter (LAD) and left ventricular ejection fraction (LVEF) accounted for 8.26% and 9.75% of the association, respectively. Conclusion: UAR is an independent predictor of LAT/SEC in patients with NVAF, outperforming its individual components and providing significant incremental value beyond the CHA 2 DS 2 -VASc score. It may serve as a readily accessible biomarker for optimizing risk stratification and clinical anticoagulation decisions. Image A is an infographic with three sections: Study Population, Exposure and Outcome, linked by arrows. Study Population features a heart icon, ECG trace and five person icons, indicating 514 NVAF cases from 2019.1 to 2022.6. Exposure shows an arm with a blood draw and a marker icon, labeled UAR (uric acid/albumin). Outcome displays a heart icon, ECG trace and five person icons, noting 89 LAT/SEC cases in NVAF patients during admission. Image B is a dose-response graph with UAR on the X-axis and Odds ratio (95% CI) on the Y-axis. The curve rises with UAR and the 95% CI band widens at higher UAR. Text indicates P for overall < 0.001 and P for nonlinear = 0.031. Image C is a decision curve analysis graph with High Risk Threshold on the X-axis and Net Benefit on the Y-axis. The legend includes UAR + CHA2DS2-VASc, CHA2DS2-VASc, All and None. The UAR + CHA2DS2-VASc curve is generally above the CHA2DS2-VASc curve, both nearing zero at higher thresholds.A three-part infographic on NVAF: UAR exposure, LAT/SEC outcome and odds and decision-curve graphs.