Abstract 16669: Left Atrial Function After Closure of Atrial Septal Defect in Adults: Comparison Between Transcatheter Closure and Surgical Closure

Abstract

Introduction: Transcatheter closure is offered as an alternative to surgery for the majority of patients with secundum atrial septal defect (ASD). However, little is known about the effect of a mechanical device on left atrial (LA) function. Hypothesis: Transcatheter closure of secundum ASD preferably preserves LA function compared with surgical closure in adult patients. Methods: We examined adult patients who underwent transcatheter (n = 58) and surgical ASD closure (n = 17) and controls (n = 20). Patients with greater than mild mitral or tricuspid regurgitation and those with a history of atrial fibrillation were not included. All the devices employed were the Amplatzer TM Septal Occluders. LA volumes were measured by the biplane area-length method using 2-dimensional transthoracic echocardiography at the onset of mitral opening (Vmax), the beginning of LA systole (Va) and the onset of mitral closure (Vmin) before and 15 ± 11 months after ASD closure. LA reservoir, conduit and booster pump functions were assessed by (Vmax-Vmin)/Vmax, (Vmax-Va)/Vmax and (Va-Vmin)/Va, respectively. Left ventricular (LV) ejection fraction was obtained to estimate LV systolic function. For the estimation of LV diastolic function, the ratio of transmitral early to late flow velocity (E/A), deceleration time of early mitral flow velocity (DT) and the ratio of systolic to diastolic pulmonary venous flow velocity (S/D) were obtained by conventional Doppler echocardiography. Results: In transcatheter closure, employed device size indexed to body surface area was 12 ± 3 mm/m 2 . Before ASD closure, there was no significant difference in all the LA parameters between the 2 groups, whereas LV ejection fraction was significantly decreased in the surgical group as compared with the transcatheter group. After ASD closure, Vmax index was significantly increased in the surgical group. LV end-diastolic volume index were significantly increased both after transcatheter and surgical ASD closure. After ASD closure, the surgery group showed significantly decreased LA reservoir and conduit functions as compared with the transcatheter group and controls. Conclusions: The transcatheter group, not surgical group, showed preserved LA function at mid-term follow-up after ASD closure.