Predictors of time to conversion of new‐onset atrial fibrillation to sinus rhythm with amiodarone therapy

BACKGROUND: New‐onset atrial fibrillation (AF) is a frequent cause of presentation to the emergency department (ED). Epicardial fat thickness (EFT) is associated with the presence and recurrence of AF. However, no study has investigated the predictors of the time to conversion of AF to sinus rhythm with amiodarone therapy. The aim of this study was to investigate predictors of time to conversion of AF to sinus rhythm in patients with new‐onset AF. METHODS: A total of 122 patients admitted to the ED with symptoms of hemodynamically stable new‐onset AF (lasting <48 hours) were registered consecutively. These patients received intravenous amiodarone. EFT was measured using 2D echocardiography in parasternal long‐axis views. RESULTS: A significant positive correlation was determined between EFT and conversion time (rho = 0.267, P = .017) in all patients. The median time for conversion from the start of amiodarone infusion was 410 min (150‐830 minutes). Based on the median conversion time, patients were classified as early conversion (time < 410 minutes; n = 41) and late conversion (time > 410 minutes; n = 40). Multivariate logistic regression analysis demonstrated that EFT (P = .033, odds ratio [OR]: 1.68, 95% confidence interval [CI]: 1.6‐2.7), higher troponin I level > 0.04 (P = .034, OR: 5.3, 95% CI: 1.1‐24.8), and lower age (P = .003, OR: 0.8, 95% CI: 0.8‐0.9) were significantly associated with longer conversion time. CONCLUSIONS: We determined that EFT and high troponin level affected the time to conversion to sinus rhythm in patients with new‐onset AF.