Intergenerational differences in the effects of transcatheter closure of atrial septal defects on cardiac function

Left Ventricular Diastolic Function in Children with Atrial Septal Defects Improves After Closure by Means of Increased Hydraulic Force

Hydraulic force aids diastolic filling of the left ventricle (LV) by facilitating basal movement of the atrioventricular plane. The short-axis atrioventricular area difference (AVAD) determines direction and magnitude of this force. Patients with atrial septal defect (ASD) have reduced LV filling due to the left-to-right shunt across the atrial septum and thus potentially altered hydraulic force. The aims were therefore to use cardiac magnetic resonance images to assess whether AVAD and thus the hydraulic force differ in children with ASD compared to healthy children, and if it improves after ASD closure. Twenty-two children with ASD underwent cardiac magnetic resonance before ASD closure. Of these 22 children, 17 of them repeated their examination also after ASD closure. Twelve controls were included. Left atrial and ventricular areas were delineated in short-axis images, and AVAD was defined as the largest ventricular area minus the largest atrial area at each time frame and normalized to body height (AVADi). At end diastole AVADi was positive in all participants, suggesting a force acting towards the atrium assisting the diastolic movement of the atrioventricular plane; however, lower in children both before (6.3 cm2/m [5.2-8.0]; p < 0.0001) and after ASD closure (8.7 cm2/m [6.6-8.5]; p = 0.0003) compared to controls (12.2 cm2/m [11.3-13.9]). Left ventricular diastolic function improves after ASD closure in children by means of improved hydraulic force assessed by AVAD. Although AVADi improved after ASD closure, it was still lower than in controls, indicating diastolic abnormality even after ASD closure. In patients where AVADi is low, ASD closure may help avoid diastolic function deterioration and improve outcome. This could likely be important also in patients with small shunt volumes, especially if they are younger, who currently do not undergo ASD closure. Changes in clinical routine may be considered pending larger outcome studies.

Atrial septal defect closure in children at young age is beneficial for left ventricular function

Aims

Atrial septal defects (ASDs) lead to volume-loaded right ventricles (RVs). ASD closure does not always alleviate symptoms or improve exercise capacity, which is possibly explained by impaired left ventricular (LV) haemodynamics. This study evaluated the effect of ASD closure in children using non-invasive LV pressure-volume (PV) loops derived from cardiac magnetic resonance (CMR) imaging and brachial blood pressure, compared with controls.

Methods and results

Twenty-three children with ASD underwent CMR, and 17 of them were re-examined 7 (6-9) months after ASD closure. Twelve controls were included. Haemodynamic variables were derived from PV loops by time-resolved LV volumes and brachial blood pressure. After ASD closure, LV volume increased [76 (70-86) vs. 63 (57-70) mL/m2, P = 0.0001]; however, it was still smaller than in controls [76 (70-86) vs. 82 (78-89) mL/m2, P = 0.048]. Compared with controls, children with ASD had higher contractility [2.6 (2.1-3.3) vs. 1.7 (1.5-2.2) mmHg/mL, P = 0.0076] and arterial elastance [2.1 (1.4-3.1) vs. 1.4 (1.2-2.0) mmHg/mL, P = 0.034]. After ASD closure, both contractility [2.0 (1.4-2.5) mmHg/mL, P = 0.0001] and arterial elastance [1.4 (1.3-2.0) mmHg/mL, P = 0.0002] decreased.

Conclusion

Despite the left-to-right atrial shunt that leads to low LV filling and RV enlargement, the LV remains efficient and there is no evidence of impaired LV haemodynamics in children. Closure of ASD at young age while the ventricle is compliant is thus beneficial for LV function. LV volumes, however, remain small after ASD closure, which may impact long-term cardiovascular risk and exercise performance.

Mid-Term Outcome of Left Ventricle Reverse Remodeling After Atrial Septal Defect Closure: A Comparison Between Surgical and Device Groups

Right ventricular (RV) volume overload occurs in patients with significant atrial septal defect (ASD II) shunts, which can impair left ventricle (LV) filling, thus decreasing LV indices. However, after ASD II closure, the left ventricle regains near normal dimensions. The purpose of this study was to compare the long-term outcomes of LV reverse remodeling between device and surgical closure. We retrospectively reviewed the echocardiographic data of 222 patients with isolated ASD II who underwent surgical (95 patients) or device closure (127 patients) between January 2012 and December 2017. The ASD II was significantly larger in the surgical closure group (p < 0.001.) leading to a higher degree of paradoxical interventricular septal (IVS) movement. In contrast, the LV volume was larger in the device closure group (p < 0.001). After a median follow-up period of 19.5 months, the maximum LV systolic and diastolic volumes were reached at 1 year in the device closure group and 2 years in the surgical closure group. IVS motion normalized in 91% of the device closure group compared to 57% of the surgical closure group (p =  < 0.001). There was significant improvement in left ventricular indices and IVS motion after ASD II closure in both groups but more favorable in patients after device closure.

The immediate haemodynamic response and right and left cardiac remodelling after percutaneous transcatheter closure of secundum atrial septal defect in children: a longitudinal cohort study

OBJECTIVE

We aimed to assess the immediate haemodynamic response and the timing of cardiac remodelling in paediatric secundum atrial septal defect patients who underwent percutaneous transcatheter closure.

METHODS

In this longitudinal cohort study with 41 paediatric secundum ASD patients who underwent PTC with Amplatzer Occluder device were assessed for immediate post-interventional haemodynamic response measured by catheterisation and was evaluated for right and left cardiac remodelling during a follow-up period of 12 months by transthoracic echocardiography. SPSS 20.0 was used for statistical analyses of pre- and post-interventional invasive haemodynamic parameters of the patients, and pre- and post-interventional TTE data compared with the values of the control group consisted of 39 healthy children.

RESULTS

The mean diameter of ASD was 13.9 ± 4.7 mm. PTC intervention in all patients completed with 100% success and 0% complication rates. All invasive haemodynamic data, except the ratio of pulmonary resistance to systemic resistance, significantly reduced after PTC (p < 0.05). TTE and PW Doppler revealed that right and left cardiac remodelling started as soon as the post-interventional 24th hour and completed in the 12th month.

CONCLUSIONS

This study with a very high interventional success rate can be counted as the first example of research on the haemodynamic response and timing of cardiac remodelling after PTC of secundum ASD in children. We suggest that future multicentric studies with larger cohorts and a comprehensive methodology like ours with longer follow-up periods would better serve to further assess the cardiac remodelling in children after PTC of secundum ASD.

Pulmonary hemodynamics and wave reflections in adults with atrial septal defects

Using high-fidelity micromanometers and flow velocity sensors at right heart catheterization, we compared pulmonary hemodynamics and wave reflections in age-matched normal adults and those with atrial septal defects, separated into three subgroups based on levels of mean pulmonary artery pressure: low (<17 mmHg), intermediate (17–26 mmHg), high (>26 mmHg). We made baseline measurements in all groups and after intravenous sodium nitroprusside in the subgroups. All of the subgroups had higher than normal baseline pulmonary flows and corresponding power that did not differ among the subgroups. The pulmonary vascular resistance, input resistance, and characteristic impedance in the subgroups did not differ from normal. Aside from the elevated flow and power, the hemodynamics in the low subgroup did not differ from normal. The intermediate subgroup had significantly higher than normal right ventricular and pulmonary artery pressures, wave reflections, and shorter wave reflection time, which all reverted to normal after nitroprusside. The high subgroup had similar changes as the intermediate subgroup. Unlike that subgroup, however, the pressures, wave reflections, and reflection return time did not revert to normal after nitroprusside. Hence, elevated wave reflections, but not resistance or characteristic impedance, are the hallmark of pulmonary hypertension in adults with atrial septal defects. Our results demonstrate that detailed measurements of hemodynamics and assessment of responsiveness to vasodilators provide important information about the pulmonary circulation in atrial septal defect. Coupled with studies after defect closure, those results may be a better foundation than current ones for clinical decisions.

Atrial septal defect (ASD) device trans-catheter closure: limitations

Transcatheter closure is a widespread technique used to treat secundum atrial septal defects (ASDs). When compared to surgery, it provides a less invasive approach with quicker recovery and reduced physical and psychological impact. Nowadays, almost 85-90% of all secundum ASD can be closed by using a transcatheter approach. However, several limitations may have a significant impact on the feasibility and success of percutaneous ASD closure. Limitations can be grouped as: (I) anatomical; (II) device-related; (III) associated defects and natural history associated issues; (IV) physiological; (V) complications. Physician should be aware of potential limits of percutaneous ASD closure.