The atrial flow regulator: current overview on technique and first experience

Ongoing and future clinical trials of device therapies for patients with heart failure

Heart failure continues to pose a significant burden in terms of morbidity, mortality, and healthcare costs worldwide despite the implementation of guideline-directed medical therapy. Addressing this challenge and improving clinical outcomes for this patient population remains an urgent priority. Recognizing the limitations in current medical approaches and exploring strategies to overcome these limitations are crucial steps toward improving future outcomes. Various device-based interventions, such as Cardiac Resynchronization Therapy devices and Left Ventricular Assist Devices, have demonstrated notable benefits for individuals with heart failure. Our review is aimed at summarizing the ongoing research into new device therapies for heart failure, emphasizing their potential to overcome the current challenges in treatment. By utilizing Clinicaltrials.gov, an online repository, we conducted a comprehensive search for trials investigating emerging device therapies for patients dealing with heart failure.

Versatility of Atrial Flow Regulator Device in Congenital Heart Disease: A Case Series

The Atrial Flow Regulator (AFR) is a self-expandable double-disk device with a central fenestration, intended to maintain a calibrated communication across the interatrial septum. Only case reports and small case series have been published about its use in the pediatric and congenital heart disease (CHD) population. We described AFR implantation in three congenital patients with different anatomies and indications. In the first case, the AFR was deployed to create a stable fenestration in a Fontan conduit, while in the second, it was used to reduce a Fontan fenestration. In the third case, we implanted an AFR to decompress the left atrium of an adolescent with complex CHD in natural history, with complete mixing, ductal-dependent systemic circulation and combined pulmonary hypertension. This case series demonstrates the great potential of the AFR device in the CHD field, showing versatility, efficacy, and safety in establishing a calibrated and stable shunt, with promising hemodynamic and symptomatic benefits.

Stent Implantation Across the Atrial Flow Regulator Device

The Atrial Flow Regulator (AFR) is a self-expandable double-disc device with a central fenestration, intended to maintain a calibrated communication across the interatrial septum. We reported for the first time a stent implantation across an AFR device in an adolescent born with complex congenital heart disease with duct-dependent systemic circulation and severe combined pulmonary hypertension.

Feasibility, Safety, and Efficacy of the Atrial Flow Regulator in Pediatric Patients: A Single-Center Experience

Background

The Atrial Flow Regulator (AFR; Occlutech) can be used to create interatrial communication with a predetermined diameter in various pathophysiological settings. In the pediatric population, the experience is limited to a few case reports. We aim to report the initial single-center experience of AFR implantation in children with congenital and acquired heart disease.

Methods

From December 2021 to June 2023, we enrolled 10 patients (aged 6 months-16 years). Indications to treatment were: left ventricular systolic dysfunction (n = 6), restrictive cardiomyopathy with pulmonary hypertension (n = 2), postoperative right ventricle dysfunction after surgical repair of a native Tetralogy of Fallot in a 12-year-old child (n = 1), and failure Fontan (n = 1). AFR implantation was successfully performed in all patients. Transseptal puncture was needed in 8 cases; in the other 2 cases, preexisting patent foramen ovale and fenestrated atrial septal defect were used. Balloon predilation was performed in 9 cases. An 8 mm device was implanted in all cases. The mean time of the procedure was 50 minutes, the median fluoroscopy time was 17 minutes, and median radiation exposure dose was 2.3 Gy × cm2.

Results

No complications were reported during the procedure. Three patients died during the follow-up: 1 due to sepsis (16 days after the procedure), 1 due to disease progression (8 months after), and 1 due to failure of ECMO decannulation 7 days after the atrial venting. In the remaining patients, a reduction of LA dilation, postcapillary pulmonary hypertension, and heart failure symptoms were observed.

Conclusions

AFR is safe and feasible in children and critical settings, allowing right/left cavities unloading and improvement of hemodynamics and symptoms.

Pediatric heart failure with preserved ejection fraction, a review

Diastolic dysfunction refers to a structural or functional abnormality of the left ventricle, resulting in impaired filling of the heart. Severe diastolic dysfunction can lead to congestive heart failure even when the left ventricle systolic function is normal. Heart failure with preserved ejection fraction (HFpEF) accounts for nearly half of the hospitalizations for acute heart failure in the adult population but the clinical recognition and understanding of HFpEF in children is poor. The condition is certainly much less frequent than in the adult population but the confirmatory diagnosis of diastolic dysfunction in children is also challenging. The underlying causes of HFpEF in children are diverse and differ from the main cause in adults. This review addresses the underlying causes and prognostic factors of HFpEF in children. We describe the pulmonary hypertension profiles associated with this cardiac condition. We discuss diagnosis difficulties in clinical practice, and we provide a simplified diagnostic algorithm for HFpEF in children.

Chronic Heart Failure in Children: State of the Art and New Perspectives

Pediatric heart failure (HF) is an important clinical condition with high morbidity and mortality. Compared to adults, pediatric HF shows different etiologies characterized by different physiology, a different clinical course, and deeply different therapeutic approaches. In the last few years, new drugs have been developed and new therapeutic strategies have been proposed with the goal of identifying an individualized treatment regimen. The aim of this article is to review the new potential drugs and non-pharmacological therapies for pediatric heart failure in children.

Feasibility, safety, and efficacy of Atrial Flow Regulator in children under 10 kg

INTRODUCTION

The Atrial Flow Regulator (AFR) is a new self-expandable percutaneous-delivered fenestrated device providing an interatrial shunt. Its use in pediatric population has been reported in failing Fontan, pulmonary hypertension, or in patients with cardiomyopathy and venoarterial extracorporeal membrane oxygenator (ECMO) support. Its use in small children under 10 kg has not been reported.

METHODS

We report the initial single center experience of the AFR implantation in children below 10 kg.

RESULTS

Four children underwent AFR implantation. Patients' age and weight ranged between 9 and 22 months and 5-8.7 kgs. Indications were to unload the left atrium during ECMO support for end-stage cardiomyopathy and to enlarge a restrictive interatrial shunt in two other patients with complex congenital heart diseases. Devices implanted were AFR-6 and AFR-8. Delivery sheaths used via venous femoral access were undersized and ranged from 9 to 11 Fr. Devices were successfully implanted and provided unrestrictive interatrial shunt in all cases. One child developed a nonocclusive thrombus in the inferior vena cava which resolved within 1 month. Clinical improvement and femoral vein patency were observed in all cases.

CONCLUSION

AFR implantation is feasible in selected children under 10 kg. The AFR can be safely deployed through sheaths that are 1-2 Fr smaller than the recommended manufacturer size. More studies are needed to confirm safety and efficacy of the device in selected pediatric patients.

Implantation of an Atrial Flow Regulator in a Child on Venoarterial Extracorporeal Membrane Oxygenator as a Bridge to Heart Transplant: A Case Report

BACKGROUND

Balloon dilation and stenting of the atrial septum are techniques used to unload left heart cavities in acute or end-stage heart failure in children. However, they carry significant risks such as tamponade or device embolization.

CASE PRESENTATION

We report the first case of a child with an end-stage mitochondrial cardiomyopathy on a venoarterial extracorporeal membrane oxygenator as a bridge to heart transplant where an atrial flow regulator device has been implanted.

CONCLUSIONS

This case illustrates the feasibility and safety of atrial flow regulator implantation in this setting. This procedure allowed to wean inotropic support while awaiting heart transplantation.