Study population and clinical follow-up
The database of a single center of patients who underwent percutaneous device closure of ASD was analyzed. Patients underwent transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) before the device closure procedure. Among the 86 consecutive patients who underwent percutaneous device closure of ASD, patients without pre- or immediate post-procedural Doppler and end-stage renal disease were excluded. In total, the clinical, transesophageal and transthoracic echocardiographic findings of 78 patients were collected at baseline, one day (immediately) after the procedure, and one-year follow-up. (Figure 1) All patients underwent blood chemistry and cell blood count analysis. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration creatinine equation.(4) Clinical characteristics, medical history, laboratory findings, medications, and echocardiographic data were collected and used for analysis. The study protocol was approved by the institutional review board of Gangnam Severance hospital (3-2020-0026), and the need for written informed consent was waived due to the study’s retrospective design.
Echocardiography at baseline and after device closure
Each patient underwent a complete standard TTE. TTE findings were collected at baseline, one day (immediately) post-closure, and one-year follow-up. LV dimensions and septal and posterior wall thickness were measured at end-diastole and end-systole in the two-dimensional (2D) parasternal long- or short-axis views. LV ejection fraction was calculated using the modified Quinones’ method.(5) LV mass was measured by Devereux’s methods as recommended by the American Society of Echocardiography.(5) LA volume was measured using the prolate ellipsoidal method at the point of LV end-systole at maximum LA size. From the apical window, a 1-mm pulsed Doppler sample volume was placed at the mitral valve tip, and mitral flow velocities from 5–10 cardiac cycles were recorded. Peak early (E) and late (A) mitral inflow velocities were also measured. Mitral annular velocity was measured by tissue Doppler imaging using the pulsed-wave Doppler mode. The filter was set to exclude high-frequency signals, and the Nyquist limit was adjusted to a range of 15–20 cm/s. Gain and sample volume were minimized to allow for a clear tissue signal with minimal background noise. Systolic (S’) and early (e’) and late diastolic velocities of the mitral annulus were measured from the apical four-chamber view with a sample volume (2–5 mm) placed at the septal corner of the mitral annulus. Peak velocity of tricuspid regurgitation was measured. Pulmonary arterial systolic pressure (PASP) was calculated as follows: 4 × tricuspid regurgitant velocity (TRV)2 + right atrial pressure, where right atrial pressure was estimated according to inferior vena cava diameter and its respiratory variations.(6) E/e’ divided by stroke volume was defined as LV end-diastolic elastance index.(7) During TEE, multiplane 2D and zoomed 3D images were acquired, and both long- and short-axis diameters of the ASD were measured. Area was calculated as long-axis diameter multiplied by short-axis diameter and 3.14. In multiple defects, the sum of all diameters or areas was used. The margins to the aorta, posterior wall, superior vena cava, and inferior vena cava rims were also evaluated.
Device implantation and periprocedural imaging
Transcatheter ASD closure was performed, as described previously(8), using various types of septal occluders (Amplatzer/Cocoon/Figullar Flex II/Gore-Helix/Occlutech). Before the procedure, the pulmonary-to-systemic blood flow ratio and pulmonary artery pressure were evaluated using cardiac catheterization. During the procedure, 3D-TEE or intracardiac echocardiography (ICE) were performed to guide accurate device implantation and ensure successful device closure. After the procedure, all patients received 100 mg/day aspirin for at least 6 months and 75 mg clopidogrel for 3 months. Other medications, such as diuretics and antihypertensive medications, were continued.
Clinical characteristics and echocardiographic parameters are presented as the means ± standard deviation for continuous variables and the numbers (percentage) for categorical variables. Correlation analysis was performed between continuous variables using the Pearson correlation coefficient. Comparisons of echocardiographic findings between two groups were performed using the independent t-test. Serial changes of echocardiographic parameters were assessed using repeated ANOVA or the paired t-test. Variables with p values less than 0.05 in univariate analysis were included in the multivariable linear or logistic regression analysis. All the analyses were performed using SPSS (version 25.0, IBM, USA), and p values less than 0.05 were considered significant.