Association of Body Mass Index with Echocardiographic Parameters and Incidence of Left Atrial Thrombus or Spontaneous Echo Contrast in Patients with Nonvalvular Atrial Fibrillation: A Cross-Sectional Study.

Background: This article focuses on the effect of body mass index (BMI) on cardiac structure and function in cases with non-valvular atrial fibrillation (NVAF). Only a few articles have investigated the relationship between BMI and the incidence of left atrial thrombus (LAT) or spontaneous echo contrast (SEC) in cases with NVAF.

Methods: This single-center retrospective study was conducted at The First People's Hospital of Changzhou. A total of 282 patients who were diagnosed with NVAF and planned to undergo radiofrequency ablation from 2019 to 2022 were enrolled in this study. None of the patients received standardized anticoagulant therapy. The patients were divided into a normal weight group, an overweight group, and an obesity group based on their BMI. The differences in echocardiographic parameters and LAT/SEC incidences among the three groups were compared, and regression analysis was applied to determine the correlation between BMI and the occurrence rates of LAT/SEC. The generalized additive model (GAM) was used to clarify the dose-response association between BMI and LAT/SEC.

Results: Left atrial diameter (LAD), left ventricular end-diastolic diameter (LVEDD), interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular ejection fraction (LVEF), right atrial diameter (RAD), and the incidences of LAT/SEC were statistically different among the three groups. Univariate and multivariate logistic regression analyses indicated that BMI was related to the incidences of LAT/SEC. For each 1-unit increase in BMI, the odds of LAT/SEC increased by 12% (odds ratio (OR): 1.12, 95% CI: 1.02, 1.24). A threshold nonlinear relationship was found using the GAM between BMI and the risk of LAT/SEC.

Conclusions: BMI significantly affects multiple echocardiographic parameters in patients with NVAF, and BMI is an independent risk factor for LAT/SEC in cases with NVAF.