An Obesity Paradox in Atrial Fibrillation Recurrence after Cardioversion: Evidence From a Vietnamese Cohort

Introduction Predictors of Atrial Fibrillation (AF) recurrence after Direct-Current Cardioversion (DCCV) remain incompletely characterized in Southeast Asian populations. About 3 months of AF recurrence rate was evaluated, and clinical and echocardiographic factors associated with early recurrence were examined in a Vietnamese cohort. Methods This single-center observational cohort study included 96 patients with AF who underwent successful DCCV between December 2022 and April 2025 at the Tam Duc Heart Hospital in Vietnam. Baseline clinical, echocardiographic, and biochemical parameters were collected. The primary outcome was AF recurrence within 3 months. Multivariable logistic regression identified independent predictors. Model discrimination was assessed using receiver operating characteristic analysis. Results AF recurred in 39 patients (40.6%). Larger Left Atrial Diameter (LAD) was independently associated with recurrence (adjusted odds ratio [aOR] per 1 mm, 1.13; 95% CI, 1.03–1.25; p = 0.011), while higher Body Mass Index (BMI) was inversely associated (aOR per 1 kg/m 2 , 0.85; 95% CI, 0.74–0.99; p = 0.038). An integrative model (LAD, BMI, age) showed modestly improved discrimination versus LAD alone (AUC 0.73 vs . 0.62; p = 0.03). Discussion Larger left atrial size reflects structural remodeling and remains a consistent predictor of AF recurrence. The inverse association between BMI and recurrence may reflect a potential obesity paradox but should be considered hypothesis-generating given the modest sample size and possible residual confounding. Conclusion Larger left atrial size and lower BMI were independently associated with early AF recurrence after successful DCCV. A simple model incorporating LAD, BMI, and age may assist preliminary risk stratification but requires external validation before clinical application.