Epicardial Fat Tissue Volume Within 1 mm of the Left Atrium Combined With Left Atrial Appendage Volume is Associated With Thrombus in Nonvalvular Atrial Fibrillation: A CCTA‐Based Risk Stratification Model

Atrial fibrillation modifies the association between CT-derived epicardial adipose tissue volume and left atrial remodeling in valvular heart disease.

BACKGROUND Epicardial adipose tissue volume (EATv) is associated with atrial fibrillation (AF), but whether AF modifies the association between EATv and atrial remodeling in valvular heart disease remains unclear. OBJECTIVE To determine whether AF modifies the association between CT-derived EATv and left atrial remodeling. METHODS This retrospective valvular surgery cohort included 436 patients (218 AF, 218 sinus rhythm [SR]) after 1:1 propensity score matching. Multivariable linear and logistic regression assessed associations of EATv with left atrial volume index (LAVI) and left atrial enlargement (LAE). Restricted cubic spline, ROC curve and mitral regurgitation-stratified sensitivity analyses were performed. Exploratory histology and EAT secretome analyses were conducted in surgical samples. RESULTS Patients with AF had higher EATv and larger atria than those with SR. In the primary adjusted model, each 10-cm3 increase in EATv was associated with a 1.21-mL/m2 higher LAVI in SR and a 4.45-mL/m2 higher LAVI in AF (P for interaction = .002). EATv was associated with LAE (OR 1.29, 95% CI 1.17-1.43), with a significant AF-by-EATv interaction (OR 1.41, 95% CI 1.15-1.74). Adding EATv improved discrimination for LAE (AUC 0.767 to 0.804; P = .007). Exploratory tissue analyses suggested adipocyte hypertrophy, fibrosis, and reduced Wnt-antagonist secretion in AF-associated EAT. CONCLUSIONS Higher CT-derived EATv was associated with more advanced left atrial remodeling, with stronger associations in AF than in SR. EATv may serve as a CT-derived marker of remodeling vulnerability in valvular heart disease.

Multimodality Quantitative Assessment of Left Atrial Remodeling Characteristics Using Echocardiography and LGE-CMR in Isolated Degenerative Mitral Regurgitation: Association With Atrial Fibrillation

A multivariable prediction model for left atrial appendage spontaneous echo contrast in patients with atrial fibrillation: development and external validation.

OBJECTIVES This study aimed to evaluate the association between LAA metabolic parameters-particularly lactic acid, glucose, and calcium-and spontaneous echo contrast, and to develop and externally validate a multivariable prediction model incorporating these indicators. METHODS Consecutive patients with AF undergoing radiofrequency catheter ablation and/or left atrial appendage occlusion were retrospectively enrolled. All patients underwent preprocedural transesophageal echocardiography with direct LAA blood sampling for metabolic analysis. An internal cohort was used for feature selection by LASSO regression and multivariable logistic regression. Model performance was assessed using ROC analysis, calibration, and decision curve analysis, with external validation in an independent cohort. RESULTS A total of 272 patients were included in the internal cohort, among whom 96 (35.3%) had SEC. Patients with SEC showed higher LAA lactic acid levels and lower LAA glucose and calcium levels. Age, persistent AF, LAA blood flow velocity, LAA lactic acid, LAA glucose, and LAA calcium were independently associated with SEC. The resulting nomogram demonstrated excellent discrimination in the internal cohort (AUC 0.895) and maintained robust performance in the external cohort (AUC 0.947). Decision curve analysis indicated a positive net clinical benefit across a wide range of threshold probabilities. CONCLUSIONS LAA metabolic characteristics, particularly elevated lactic acid levels, are independently associated with SEC in AF. A prediction model integrating metabolic, clinical, and echocardiographic parameters provides robust and externally validated risk stratification for SEC.

Left Atrial Strain Prediction of New-Onset Atrial Fibrillation in Apical Hypertrophic Cardiomyopathy with Cardiac MRI.

Purpose To evaluate the predictive value of cardiac MRI-derived left atrial strain (LAS) for new-onset atrial fibrillation (AF) in apical hypertrophic cardiomyopathy (AHCM). Materials and Methods This retrospective study included patients with AHCM with no prior history of AF who underwent 3.0-T cardiac MRI between May 2016 and December 2023. LAS parameters-reservoir strain (εs), conduit strain (εe), and booster pump strain (εa)-and minimum left atrial volume index (LAVImin) were measured. The clinical end point was new-onset AF as confirmed with electrocardiography, Holter monitoring, or implantable cardiac devices. Cox proportional hazards models and time-dependent receiver operating characteristic (ROC) analyses were performed to evaluate associations and discriminatory performance for new-onset AF. Results A total of 156 patients (mean age, 51.0 years ± 11.5 [SD]; 113 male) were included. During a median follow-up of 33 months, AF occurred in 21 patients. In multivariable Cox models adjusted for age, body mass index, and LAVImin, LAS parameters were independently associated with incident AF (εs: hazard ratio [HR], 0.79 [95% CI: 0.69, 0.90], P < .001; εa: HR, 0.65 [95% CI: 0.50, 0.83], P < .001; and εe: HR, 0.79 [95% CI: 0.65, 0.95], P = .01). In the nested Cox models, adding LAS to a baseline clinical-volumetric model improved model fit and discrimination, with the χ2 value improving from 36.22 to 54.90 and the concordance index value improving from 0.846 to 0.930 (P < .001 for both). The LAVImin provided complementary prognostic information, with its contribution varying across strain-specific models. Time-dependent ROC analyses demonstrated that LAS identified the development of AF well across prespecified time horizons. Conclusion Cardiac MRI-derived LAS was independently associated with new-onset AF in AHCM and provided incremental prognostic value beyond routine clinical and left atrial volumetric measures. Keywords: Apical Hypertrophic Cardiomyopathy, Atrial Fibrillation, Cardiac MRI, Left Atrial Strain, Heart, Cardiomyopathies, MR Imaging Supplemental material is available for this article. © RSNA, 2026.

Quantitative MRI assessment of left ventricular filling: associations with left atrial and pulmonary artery dimensions in a population-based study

Introduction Left ventricular diastolic dysfunction is associated with left atrial remodeling and alterations of the pulmonary circulation. However, whether these interconnected changes across the cardiopulmonary axis can be simultaneously characterized using a non-dedicated whole-body MRI examination in individuals free of overt cardiovascular disease remains unclear. Methods 339 subjects (mean age 56.4 years; 43.4% female) without overt cardiovascular disease were included. Linear regression models, adjusted for age, sex, and cardiovascular risk factors, explored the association of Left ventricle (LV) filling rates with left atrium (LA) size and function, and mean pulmonary artery (MPA). Results Average maximal LA was 19.6 cm2, minimal LA 11.8 cm2, area-based LA function 39.8%, non-electrocardiogram-synchronized LA size 16.8 cm2, LV early filling rate 227.1 mL/s, late filling rate 238.4 mL/s, and MPA diameter 2.67 cm. Higher early and late LV filling rates were associated with larger maximal LA size across all models (β = 2.30; β = 1.00), minimal LA size (β = 1.41; β = 0.77), and non-electrocardiogram-synchronized LA size (β = 1.86; β = 0.90, all p < 0.001, fully adjusted model). Higher early LV filling rates, but not higher late LV filling rates, were associated with larger MPA diameter across all models (β = 0.06, p = 0.03, fully adjusted model). Conclusion In individuals free of overt cardiovascular disease, MRI-derived LV filling dynamics were associated with structural alterations of the left atrium and pulmonary vasculature, suggesting that changes across the cardiopulmonary axis may already be detectable by whole-body MRI before clinical disease becomes apparent.

Prediction of Left Atrial Appendage Dysfunction by Atrial Strain Imaging in Patients with Rheumatic Mitral Stenosis in Sinus Rhythm

In severe rheumatic mitral stenosis with sinus rhythm, left atrial appendage (LAA) dysfunction increases thromboembolic risk, yet clinical guidelines provide no recommendations, and its assessment via transesophageal echocardiography is not feasible for routine or repeated use. This study assessed whether left atrial (LA) strain imaging could noninvasively predict LAA contractile dysfunction. We prospectively enrolled 138 patients with severe rheumatic MS in sinus rhythm who underwent transthoracic and transesophageal echocardiography. LAA inactivity was defined as LAA emptying velocity <25 cm/s. LA reservoir (LASr), conduit, and contractile strain were quantified using speckle-tracking echocardiography. Multivariable logistic regression and receiver-operating characteristic (ROC) analyses were performed to evaluate predictors of LAA inactivity. LAA inactivity was observed in 108 patients (78.2%), and LAA thrombus was detected in 8 patients (5.8%)—all in sinus rhythm. In multivariate analysis, LASr was the strongest independent predictor of LAA inactivity (OR 0.61 per 1% increase; 95% CI: 0.50–0.75; p < 0.0001). LASr yielded an AUC of 0.950 (95% CI: 0.911-0.989), with a threshold of ≤22.95% showing a sensitivity of 93.5%, and specificity of 90% for predicting LAA inactivity. Impaired LA strain identified patients with elevated fibrinogen, D-dimer, and the presence of LAA thrombus. LA strain imaging provides a robust noninvasive predictor of LAA dysfunction in severe rheumatic MS patients in sinus rhythm. These findings support the potential clinical utility of LA strain in improving risk stratification and guiding anticoagulation decisions in this under-recognized high-risk population.