Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

First in-human modified atrial septostomy combining radiofrequency ablation and balloon dilation

OBJECTIVE

Preclinical research suggests that the combined use of radiofrequency ablation and balloon dilation (CURB) could create stable interatrial communications without device implantation. This study examined the first in-human use of CURB for modified atrial septostomy in patients with severe pulmonary arterial hypertension (PAH).

METHODS

Between July 2018 and October 2021, CURB was performed in 19 patients with severe PAH (age: 31.5±9.1 years; mean pulmonary artery pressure: 73 mm Hg (IQR: 66-92); pulmonary vascular resistance: 18.7 Wood units (IQR: 17.8-23.3)). Under guidance of intracardiac echocardiography and three-dimensional location system, (1) fossae ovalis was reconstructed and ablated point-by-point with radiofrequency; (2) then graded balloon dilation was performed after transseptal puncture and the optimal size was determined according to the level of arterial oxygen saturation (SatO₂); (3) radiofrequency ablation was repeated around the rims of the created fenestration. The interatrial fenestrations were followed-up serially.

RESULTS

After CURB, the immediate fenestration size was 4.4 mm (IQR: 4.1-5.1) with intracardiac echocardiography, systolic aortic pressure increased by 10.2±6.9 mm Hg, cardiac index increased by 0.7±0.3 L/min/m² and room-air resting SatO2 decreased by 6.2±1.9% (p<0.001). One patient experienced increased pericardiac effusion postoperatively; the others had no complications. On follow-up (median: 15.5 months), all interatrial communications were patent with stable size (intraclass correlation coefficient=0.96, 95%CI:0.89 to 0.99). The WHO functional class increased by 1 (IQR: 1-2) (p<0.001) with improvement of exercise capacity (+159.5 m, P<0.001).

CONCLUSION

The interatrial communications created with CURB in patients with severe PAH were stable and the mid-term outcomes were satisfactory.

TRIAL REGISTRATION NUMBER

NCT03554330.

Elective Non-Urgent Balloon-Atrial Septostomy in Infants with d-Transposition of the Great Arteries Does Not Eliminate the Need for PGE1 Therapy at the Time of Arterial Switch Operation

Once a mainstay in the treatment of neonates with d-transposition of the great arteries (d-TGA), the application of balloon atrial septostomy (BAS) in the d-TGA population has become more selective. Currently, there is no clear evidence for or against a selective BAS strategy. The aims of this single-center retrospective study were to determine the incidence of BAS in the neonatal d-TGA population in the current era, to measure the rate of procedural success, and to compare the outcomes and complication rates of patients who underwent BAS to those who underwent neonatal ASO alone. Between 2012 and 2018, 147 patients with d-TGA underwent initial medical management and ASO, 73 of which underwent BAS. The percentage of patients that underwent BAS decreased from 73 to 33% over the study time period. In patients with d-TGA with intact ventricular septum, 33% of patients remained off of PGE₁ at the time of surgery regardless of BAS. In d-TGA with ventricular septal defect, 85.7% of those that underwent BAS and 54.1% of those who did not remained off of PGE₁ at the time of surgery, however, this difference did not reach statistical significance. In this single institution retrospective cohort of patients with d-TGA, the performance of a technically successful balloon atrial septostomy did not eliminate the need for PGE₁ therapy at the time of definitive ASO. This was true regardless of the presence or absence of a ventricular septal defect.

Ductal Stenting to Retrain the Involuted Left Ventricle in d-Transposition of the Great Arteries

BACKGROUND

Ductal stenting is performed to retrain involuted left ventricles (LVs) in patients with d-transposition of the great arteries and intact ventricular septum (TGA-IVS). However, its efficacy is largely unknown. This study aimed to determine the safety and efficacy of ductal stenting in retraining of the involuted LV in patients with TGA-IVS.

METHODS

This was a single-center, retrospective study. Echocardiographic assessment of the LV geometry, mass, and free wall thickness was performed before stenting and before the arterial switch operation. Patients then underwent the arterial switch operation, and the postoperative outcomes were reviewed.

RESULTS

There were 11 consecutive patients (male, 81.8%; mean age at stenting, 43.11 ± 18.19 days) with TGA-IVS with involuted LV who underwent LV retraining by ductal stenting from July 2013 to December 2017. Retraining by ductus stenting failed in 4 patients (36.3%). Two patients required pulmonary artery banding, and another 2 had an LV mass index of less than 35 g/m². Patients in the successful group had improved LV mass index from 45.14 ± 17.91 to 81.86 ± 33.11g/m² (p = 0.023) compared with 34.50 ± 10.47 to 20.50 ± 9.88 g/m² (p = 0.169) and improved LV geometry after ductal stenting. The failed group was associated with an increased need for extracorporeal support (14.5% vs 50%, p = 0.012). An atrial septal defect-to-interatrial septum length ratio of more than 0.38 was associated with failed LV retraining.

CONCLUSIONS

Ductal stenting is an effective method to retrain the involuted LV in TGA-IVS. A large atrial septal defect (atrial septal defect-to-interatrial septum length ratio >0.38) was associated with poor response to LV retraining.

Balloon atrial septostomy at the bedside versus the catheterisation laboratory

A shorter umbilical venous approach provides an opportunity for balloon atrial septostomy in the younger neonate as opposed to those who present at the end of first week of life. However, the ideal choice of access for a bedside balloon atrial septostomy is not well established. Wouldn't prostaglandin infusion be a safer option for transport of babies with dextro-transposition in the neonatal period, when the arterial duct can be kept open? A prenatal diagnosis of dextro-transposition facilitates monitoring and planning of septostomy in the early neonatal period explaining why babies underwent bedside procedures more often.