Feasibility, safety and midterm follow-up of patients after nonsurgical closure of atrial septal defects using very large 40-46 mm nitinol septal occluders

Arrhythmic Risk and Treatment after Transcatheter Atrial Septal Defect Closure

Atrial septal defect (ASD) represents the most common congenital heart defect identified in adulthood. Atrial and ventricular geometric remodeling due to intracardiac shunt increase the risk of arrhythmias, especially atrial fibrillation (AF). Clinical, echocardiography, electrocardiogram, and device-related predictors may be used to assess the risk of atrial arrhythmias after ASD closure. The underlying mechanisms in these patients are complex and at least in part independent of the structural remodeling secondary to hemodynamic overload. Device closure of the ASD itself and its timing impact future arrhythmia risk, as well as posing a challenge for when transseptal puncture is required. Sudden cardiac death (SCD) risk is higher than in the general population and an implantable cardioverter-defibrillator (ICD) may be indicated in selected cases.

Experience with the largest custom-made 48 mm fenestrated atrial septal occluder device and its 4-year follow-up

Atrial septal defects (ASDs) measuring <38 mm are referred for transcatheter closure. Availability of larger devices up to 46 mm extended the inclusion criteria. An elderly hypertensive male with a 44 mm secundum ASD and coexistent sick sinus syndrome and atrioventricular (AV) nodal block presented with syncope. Balloon interrogation unmasked restrictive left ventricular (LV) physiology. After AV synchronous pacing, balloon-assisted deployment of a custom fenestrated 48 mm Figulla septal occluder (Occlutech Inc., Schaffhausen, Switzerland) prevented a rise of LV end-diastolic pressures beyond 12 mmHg. Echocardiogram and computed tomography after 4 years confirmed a patent fenestration and favorable remodeling. This report of the clinical use of the largest ASD device demonstrated the feasibility of closure of extremely large defects despite a restrictive LV.

Transcatheter closure of multiple secundum atrial septal defects using multiple occluder devices: A comparative experience between pediatric and adult patients

Background:

Device closure of multiple atrial septal defects (MASDs) is frequently done using a single centrally deployed septal or cribriform occluder, but multiple devices are needed for large defects separated more than 6 mm. There is a concern about complications while using multiple devices, especially in children.

Methods:

Patients who received multiple devices for closure of MASD were grouped according to their age and analyzed for procedural techniques, immediate and late complications. MASDs closed by a single device were not included. Balloon sizing was done when echocardiographic images were suboptimal before simultaneous device deployment through two venous accesses or sequential deployment through one access. Duration and number of antiplatelet drugs and residual flows were analyzed on follow-up.

Results:

Twenty-five patients received multiple devices. Balloon interrogation was performed in 16/18 adults but only in 2/7 children. Device size was 2–5 mm larger than echocardiographic defect size or equal to balloon waist. There were no procedural failures; 7/25 showed small postprocedural residual flows. Complications including embolization in one, arrhythmia in one, and cobra deformity in two were managed successfully. On a median follow-up of 5.5 years (1–12 years), residual flows disappeared in 4/7 and there were no major late complications.

Conclusions:

Use of multiple devices for closing MASD is feasible with good technical success. Echocardiography and balloon interrogation are the keys for success. Simultaneous deployment is often needed and sequential delivery is feasible rarely if the defects are far apart. Minor residual leaks are common but improve on follow-up. There are no significant new complications on long-term follow-up.

Percutaneous secundum atrial septal defect closure for the treatment of atrial arrhythmia in the adult: A meta-analysis

BACKGROUND

Atrial arrhythmias are common in patients with atrial septal defects (ASD) but the effects of percutaneous closure on atrial arrhythmia prevalence is unclear. We investigated the effects of ASD device closure and the impact of age at time of closure on prevalent atrial arrythmia.

METHODS

Meta-analysis of studies reporting atrial arrhythmia prevalence in adult patients before and after percutaneous closure was performed. Primary outcomes were prevalence of 'all atrial arrhythmia' and atrial fibrillation alone post closure. Sub-group analysis examined the effects of closure according to age in patients; <40 years, ≥40 and ≥ 60 years. 25 studies were included.

RESULTS

Meta-analysis of all studies demonstrated no reduction in all atrial arrhythmia or atrial fibrillation prevalence post-closure (OR 0.855, 95% CI 0.672 to 1.087, P = .201 and OR 0.818, 95% CI 0.645 to 1.038, P = .099, respectively). A weak reduction in all atrial arrhythmia and atrial fibrillation was seen in patients ≥40 years (OR 0.77, 95% CI 0.616 to 0.979, P = .032 and OR 0.760, 95% CI 0.6 to 0.964, P = .024, respectively) but not ≥60 years (OR 0.822, 95% CI 0.593 to 1.141, P = .242 and OR 0.83, 95% CI 0.598 to 1.152, P = .266, respectively). No data were available in patients <40 years. This, and other limitations, prevents conclusive assessment of the effect of age on arrhythmia prevalence.

CONCLUSIONS

Overall, percutaneous ASD closure is not associated with a reduction in atrial arrhythmia prevalence in this meta-analysis. A weak benefit is seen in patients ≥40 years of age, not present in patients ≥60 years.

Prediction of hemodynamics after atrial septal defect closure using a framework of circulatory equilibrium in dogs

In patients with heart failure, atrial septal defect (ASD) closure has a risk of inducing life-threatening acute pulmonary edema. The objective of this study was to develop a novel framework for quantitative prediction of hemodynamics after ASD closure. The generalized circulatory equilibrium comprises right and left cardiac output (CO) curves and pulmonary and systemic venous return surfaces. We incorporated ASD into the framework of circulatory equilibrium by representing ASD shunt flow (Q_ASD) by the difference between pulmonary flow (Q_P) and systemic flow (Q_S). To examine the accuracy of prediction, we created ASD in six dogs. Four weeks after ASD creation, we measured left atrial pressure (P_LA), right atrial pressure (P_RA), Q_P, and Qs before and after ASD balloon occlusion. We then predicted postocclusion hemodynamics from measured preocclusion hemodynamics. Finally, we numerically simulated hemodynamics under various ASD diameters while changing left and right ventricular function. Predicted postocclusion P_LA, P_RA, and Q_S from preocclusion hemodynamics matched well with those measured [P_LA: coefficient of determination (r²) = 0.96, standard error of estimate (SEE) = 0.89 mmHg, P_RA: r² = 0.98, SEE = 0.26 mmHg, Q_S: r² = 0.97, SEE = 5.6 mL·min^-1·kg^-1]. A simulation study demonstrated that ASD closure increases the risk of pulmonary edema in patients with impaired left ventricular function and normal right ventricular function, indicating the importance of evaluation for the balance between right and left ventricular function. ASD shunt incorporated into the generalized circulatory equilibrium accurately predicted hemodynamics after ASD closure, which would facilitate safety management of ASD closure.NEW & NOTEWORTHY We developed a framework to predict the impact of atrial septal defect (ASD) closure on hemodynamics by incorporating ASD shunt flow into the framework of circulatory equilibrium. The proposed framework accurately predicted hemodynamics after ASD closure. Patient-specific prediction of hemodynamics may be useful for safety management of ASD closure.