Temporary balloon occlusion test can overestimate the risk of acute pulmonary edema after transcatheter atrial septal defect closure

BACKGROUND

Atrial septal defect (ASD) closure can cause acute pulmonary edema. Before transcatheter closure is performed, temporary balloon occlusion test (BOT) is recommended in patients with left ventricular dysfunction to predict the risk of pulmonary edema. However, the accuracy of BOT has not been verified. This study aimed to compare hemodynamic differences between BOT and transcatheter closure.

METHODS

A total of 42 patients with a single ASD over age 18 years who underwent BOT before transcatheter ASD closure between October 2010 and May 2020 were analyzed. Pulmonary capillary wedge pressure (PCWP) was measured using a Swan-Ganz catheter placed in the pulmonary artery at baseline, after 10 min of BOT, and after transcatheter closure. Amplatzer septal occluder was used for all transcatheter closures.

RESULTS

Mean patient age was 64 ± 18 years (range, 18-78). Mean ASD diameter and pulmonary to systemic flow ratio were 18 ± 5 and 2.8 ± 1.0 mm, respectively. Mean PCWP at baseline, during BOT, and after transcatheter closure was 8.9 ± 2.9, 13.5 ± 4.2, and 9.5 ± 2.6 mmHg, respectively. The difference between BOT and after transcatheter closure values was significant (p < 0.001). During BOT, PCWP increased ≥18 mmHg in 7 patients, whereas after ASD closure, PCWP was <18 mmHg in all 7 and none developed acute pulmonary edema.

CONCLUSION

Temporary balloon occlusion of an ASD and transcatheter ASD closure result in different hemodynamic change. BOT overestimates increase of PCWP after transcatheter ASD closure and requires careful interpretation. Well-designed, larger studies in higher-risk patients are warranted to verify the clinical implications of BOT in more detail.

Effectiveness and Safety of Transcatheter Atrial Septal Defect Closure in Adults with Systemic Essential Hypertension

Concomitant systemic essential hypertension (HTN) in adults with a secundum atrial septal defect (ASD) can unfavorably affect the hemodynamics and transcatheter ASD closure (ASDC) effects. This study aims to assess the effectiveness and safety of ASDC in adults with HTN in real-world clinical practice. Right ventricular (RV) reverse remodeling (RVR) and the lack of a left-to-right interatrial residual shunt (NoRS) in echocardiography 24 h and 6 months (6 M) post-ASDC, and ASDC-related complications within 6 M were evaluated in 184 adults: 79 with HTN (HTN+) and 105 without HTN (HTN−). Compared to HTN−, HTN+ patients were older and had a greater RV size and the prevalence of atrial arrhythmias, chronic heart failure, nonobstructive coronary artery disease, diabetes, hyperlipidemia, and left ventricular diastolic dysfunction. ASDC was successful and resulted in RVR, NoRS, and a lack of ASDC-related complications in the majority of HTN+ patients both at 24 h and 6 M. HTN+ and HTN− did not differ in ASD size, a successful implantation rate (98.7% vs. 99%), RVR 24 h (46.8% vs. 46.7%) and 6 M (59.4% vs. 67.9%) post-ASDC, NoRS 24 h (79% vs. 81.5%) and 6 M (76.6% vs. 86.9%) post-ASDC, and the composite of RVR and NoRS at 6 M (43.8% vs. 57.1%). Most ASDC-related complications in HTN+ occurred within 24 h and were minor; however, major complications such as device embolization within 24 h and mitral regurgitation within 6 M were observed. No differences between HTN+ and HTN− were observed in the total (12.7% vs. 9.5%) and major (5.1% vs. 4.8%) complications. Transcatheter ASDC is effective and safe in adults with secundum ASD and concomitant HTN in real-world clinical practice; however, proper preprocedural management and regular long-term follow-up post-ASDC are required.

Left ventricular restrictive physiology in kids with atrial septal defects: Something unexpected!

Atrial septal defect (ASD) associated with left ventricular (LV) diastolic dysfunction (DD) is rare in children. DD is common in elderly patients undergoing ASD closure. Restrictive physiology among children undergoing percutaneous ASD closure is something unexpected that has not been described before in the literature. Hence, we report a child referred to our center for ASD closure in whom an LV DD has been unmasked with a balloon occlusion test and has been managed with pharmacological preconditioning and subsequent ASD closure with good outcome. Albeit rare, LV DD can occur in children undergoing ASD closure.

Current practice in atrial septal defect occlusion in children and adults

INTRODUCTION

Atrial septal defect (ASD) is one of the most common congenital heart diseases (CHD) in children and adults. This group of malformations includes several types of atrial communications allowing shunting of blood between the systemic and the pulmonary circulations. Early diagnosis and treatment carries favorable outcomes. Patients diagnosed during adulthood often present with complications related to longstanding volume overload such as pulmonary artery hypertension (PAH), atrial dysrhythmias, and right (RV) and left (LV) ventricular dysfunction.

AREA COVERED

This article intended to review all aspects of ASD; anatomy, pathophysiology, clinical presentation, natural history, and indication for treatment. Also, we covered the transcatheter therapy in detail, including the procedural aspect, available devices, and outcomes.

EXPERT OPINION

There has been a remarkable improvement in the treatment strategy of ASD over the last few decades. Transcatheter closure of ASD is currently accepted as the treatment of choice in most patients with appropriately selected secundum ASDs. This review will focus on the most recent advances in diagnosis and treatment strategy of secundum ASD.

Hemodynamic assessment of atrial septal defects

Atrial septal defect (ASD) is one of the most common congenital cardiac anomalies. ASD can present as an isolated lesion in an otherwise normal heart or in association with other congenital heart conditions. Regardless of the type of ASD, the direction and degree of shunting across the communication is mainly determined by the difference in compliance between the right and left ventricle. Hemodynamics in children is characterized by left-to-right shunting, dilated right heart structures and normal pulmonary artery pressures (PAP). Patients diagnosed at adult age often present with complications related to long-standing volume overload such as pulmonary artery hypertension and right and left ventricular dysfunction. Diagnostic catheterization is usually not indicated unless there is suggestion of pulmonary hypertension on echocardiography. In older patients and/or in those with ventricular dysfunction, measurement of left heart pressures during temporary balloon occlusion is recommended prior to device closure as it may not be tolerated. In ASD associated with other congenital malformations, shunting degree and direction will depend upon underlying condition. Restrictive ASD can result in significant hemodynamic compromise in neonates with conditions such as hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA). In most cases, hemodynamics can be estimated with echocardiography only.

Efficacy and safety of transcatheter closure in adults with large or small atrial septal defects

Background

In most patients with secundum atrial septal defects (ASD), transcatheter closure is the preferred treatment strategy, but whether device size affects clinical outcomes is unknown. We sought to study the efficacy and safety of large closure devices compared to the use of smaller devices.

Methods

Using a single-center, prospective registry of adult patients undergoing transcatheter ASD closure, patients receiving a large closure device (waist diameter ≥25 mm, n = 41) were compared to patients receiving smaller devices (waist diameter ≤24 mm, n = 66). We analyzed pre-interventional clinical, hemodynamic and echocardiographic data, interventional success and complication rates, and 6-month clinical and echocardiographic outcomes. The primary efficacy outcome was successful ASD closure achieved by a single procedure and confirmed by lack of a significant residual shunt at 6 months. The primary safety outcome was a composite of device embolization, major bleeding, and new-onset atrial arrhythmia occurring within 6 months.

Results

Transcatheter ASD closure using large devices was successful in 90 % compared to 97 % of patients receiving smaller devices as defined by the primary efficacy outcome (p = 0.20). The primary safety outcome occurred in 4 patients of the large and 6 patients of the small device group, resulting in an event-free rate of 90 and 91 %, respectively (p = 0.89). Similar significant symptomatic improvement was observed in both treatment groups after 6 months, indicated by a 50 % increase in the fraction of patients in NYHA class I (p < 0.0001 vs. baseline).

Conclusions

Transcatheter closure in this cohort of patients with large or small ASD was effective with similar complication rates during short-term follow-up irrespective of the size of the implanted device.

Pulmonary edema following transcatheter closure of atrial septal defect

We describe an incident of development of acute pulmonary edema after the device closure of a secundum atrial septal defect in a 52-year-old lady, which was treated with inotropes, diuretics and artificial ventilation. Possibility of acute left ventricular dysfunction should be considered after the defect closure in the middle-aged patients as the left ventricular compliance may be reduced due to increased elastic stiffness and diastolic dysfunction. Baseline left atrial pressure may be > 10 mmHg in these patients. Associated risk factors for the left ventricular dysfunction are a large Qp:Qs ratio, systemic hypertension, severe pulmonary hypertension and paroxysmal atrial fibrillation.

Sox18 preserves the pulmonary endothelial barrier under conditions of increased shear stress

Shear stress secondary to increased pulmonary blood flow (PBF) is elevated in some children born with congenital cardiac abnormalities. However, the majority of these patients do not develop pulmonary edema, despite high levels of permeability inducing factors. Previous studies have suggested that laminar fluid shear stress can enhance pulmonary vascular barrier integrity. However, little is known about the mechanisms by which this occurs. Using microarray analysis, we have previously shown that Sox18, a transcription factor involved in blood vessel development and endothelial barrier integrity, is up-regulated in an ovine model of congenital heart disease with increased PBF (shunt). By subjecting ovine pulmonary arterial endothelial cells (PAEC) to laminar flow (20 dyn/cm(2) ), we identified an increase in trans-endothelial resistance (TER) across the PAEC monolayer that correlated with an increase in Sox18 expression. Further, the TER was also enhanced when Sox18 was over-expressed and attenuated when Sox18 expression was reduced, suggesting that Sox18 maintains the endothelial barrier integrity in response to shear stress. Further, we found that shear stress up-regulates the cellular tight junction protein, Claudin-5, in a Sox18 dependent manner, and Claudin-5 depletion abolished the Sox18 mediated increase in TER in response to shear stress. Finally, utilizing peripheral lung tissue of 4 week old shunt lambs with increased PBF, we found that both Sox18 and Claudin-5 mRNA and protein levels were elevated. In conclusion, these novel findings suggest that increased laminar flow protects endothelial barrier function via Sox18 dependent up-regulation of Claudin-5 expression.

ASD closure under pressure

Transcatheter atrial septal defect device implantation in elderly patients may cause acute pulmonary oedema when impaired left ventricular diastolic function causes an abrupt increase in left atrial pressure. Though left atrial pressure is often monitored during test occlusion of a defect, it is not clear at what cut-off value device implantation is contraindicated. We report successful closure of an atrial septal defect in a 73-year-old patient, even though the mean left atrial pressure increased from 18 to 25 mm Hg with device implantation. Although a fenestrated device was used, this did not prevent the rise in left atrial pressure. The patient was supported with mechanical ventilation, milrinone and intravenous diuretics following the procedure and did not develop pulmonary oedema. Her dyspnoea improved and her functional status increased from New York Heart Association (NYHA) III to NYHA II. In conclusion, successful device closure can be accomplished even with high left atrial pressure.

The ERK1/2 signaling pathway is involved in sulfur dioxide preconditioning-induced protection against cardiac dysfunction in isolated perfused rat heart subjected to myocardial ischemia/reperfusion

Ischemia/reperfusion injury (IRI) occurs frequently during reperfusion of ischemic myocardium, and preconditioning has been regarded as one of the best strategies to prevent myocardial injury during the ischemia/reperfusion process. Our previous studies indicated that a small dose of sulfur dioxide (SO₂) used as preconditioning exerts cardioprotection. However, the mechanisms underlying the cardioprotection remain unclear. The present study was designed to examine if the extracellular regulated protein kinases 1/2 (ERK1/2) signaling pathway mediated protection against cardiac dysfunction after SO₂ preconditioning in isolated rat hearts subjected to ischemia/reperfusion (I/R). Langendorff heart perfusion was performed in vitro, where 56 male Wistar rats were randomly divided into seven groups: control group, 5 μmol/L SO₂ group (S5), 2-(2-Amino-3-methoxyphenyl)-4H-1-benzopyran-4-one (PD98059) + 5 μmol/L SO₂ (PD98059 + S5) group, PD98059 group, I/R group, 5 μmol/L SO₂ + I/R (S5 + I/R) group and PD98059 + 5 μmol/L SO₂ + I/R (PD98059 + S5 + I/R) group. Cardiac function and myocardial phosphorylated ERK1/2 protein were measured. We found that I/R in isolated rat heart resulted in cardiac dysfunction with a significant increase in phosphorylated ERK1/2 protein. SO₂ preconditioning markedly suppressed phosphorylated ERK1/2 protein and improved cardiac function in isolated rat heart with I/R (p < 0.05). However, pre-treatment with PD98059 could prevent the above effects of SO₂ preconditioning. In conclusion, SO₂ preconditioning protected against cardiac dysfunction in isolated rat heart subjected to I/R via suppression of the over-activation of the ERK1/2 signaling pathway.