3-dimensional transthoracic and transesophageal echocardiography characterization of the right atrial appendage according to AF pattern

Abstract Introduction Few studies have described the morphology and function of the right atrial appendage (RAA). Purpose This study aimed to assess whether 3D transoesophageal echocardiography (TOE) can characterize RAA anatomy and function in patients with atrial fibrillation (AF). Methods This prospective study evaluated 202 patients hospitalized at admission for AF using 2D transthoracic echocardiography (TTE) and 2D/3D transoesophageal echocardiography (TOE). Patients were categorized according to their AF pattern at admission as either paroxysmal (n=60) or persistent AF (n=142). 2D and 3D parameters were analysed offline. 2D RAA spontaneous echo contrast, 2D end-systolic (ES) and end-diastolic (ED) RAA ostium diameters, 2D ES/ED RAA depth, 2D ES/ED RAA areas, 3D ES/ED RAA volumes, 3D RAA emptying fraction, and 3D RAA morphology were assessed (Figure 1). Results Median age (interquartile range [IQR]) was 67.1 (59.9–74.1) years, 126 (62.4%) were male, and 153 (75.7%) had a CHA2DS2-VASc score ≥2. Median (IQR) 2D ES RAA area was 4.7 (3.4–6.3) cm2 and 3D ES RAA volume was 15.4 (11.1–21.9) mL. On 2D TTE, patients with persistent AF displayed significantly lower left ventricular ejection fraction (LVEF) and subaortic velocity time integral, and significantly higher atrial volumes, E/e’ ratios, and pulmonary artery systolic pressure. Regarding TOE RAA evaluation, patients with persistent AF demonstrated significantly larger 2D ES and ED RAA measurements (2D RAA ostium maximal diameter, depth, and area, and 3D ES and ED RAA volumes). They exhibited a lower RAA filling velocity and 3D RAA ejection fraction and more frequently had an RAA pyramid morphology, compared to "bowl" morphology (Table 1). Conclusion A new 3D TOE method can accurately define geometry, size, and function of the RAA in patients with AF. Consequently, analyzing RAA remodeling in AF is feasible and may be useful in atrial fibrillation risk stratification.Figure 1 Table 1