Heart failure: what is atrial flow regulator?

By Cristiano Antonino On Aug 12, 2023

The atrial flow regulator is an innovative, state-of-the-art, minimally invasive technique to treat heart failure that cannot be controlled with drugs and offer patients a better life expectancy and quality of life

The atrial flow regulator in the treatment of heart failure

Heart failure, or cardiac insufficiency, is a syndrome characterised by a chronic course associated with mortality.

Approximately 30 million people worldwide suffer from it; and factors such as an ageing population, obesity, diabetes and high blood pressure increase the prevalence of this pathological condition.

Cardiac dysfunction, which occurs when the heart fails to supply adequate blood to the organs and manifests itself in breathing difficulties, fatigue, accelerated heartbeat, abdominal bloating, leg oedema, can have various causes including hypertension, heart attack, hereditary predisposition, inflammatory diseases, and is bound to worsen over time.

The heart muscle is therefore unable to fulfil its normal contractile pump function and thus properly supply blood to the organs and the body’s needs.

Although there are pharmacological treatments suitable for the treatment of heart failure, the therapy is not always fully effective and patients do not see improvements in their symptoms, resulting in an increase in hospitalisations.

Diastolic dysfunction and increased left ventricular stiffness cause increased filling pressures resulting in atrial volume overload and pulmonary congestion.

This occurs both in patients with heart failure with preserved ejection fraction (HFpEF) and in patients with reduced ejection fraction (HFrEF).

In patients with preserved ejection fraction heart failure, an excessive increase above a certain threshold in pulmonary capillary pressure during exercise, despite normal values at rest, has been shown to be associated with increased mortality.

In patients with reduced ejection fraction, on the other hand, diastolic dysfunction remains impaired despite adequate medical therapy and is highly predictive of worse outcomes.

Reducing left atrial pressure and volume overload of the left atrium by creating a communication channel at the level of the interatrial septum has emerged as a new treatment option to improve the symptoms of patients with heart failure refractory to optimal medical therapy.

What is the Atrial Flow Regulator?

The Atrial Flow Regulator, AFR, is a device intended for the treatment of symptoms associated with heart failure in both heart failure patients with preserved (HFpEF) and reduced (HFrEF) ejection fraction.

It is a state-of-the-art innovation for the treatment of patients who do not respond adequately to medical therapies or without significant treatment alternatives.

The device consists of a network of self-expanding Nitinol (a special metal alloy) wires, a flexible body connects the two retention discs and in the centre is a fenestration for the shunt, the communication channel.

On the proximal disc of the device, i.e. the right atrial side, there is a ball connector that acts as an adapter for the release system during positioning, preventing excessive tension on the septum.

It is a safe and simple device to implant.

Its purpose is to protect and preserve the result of an atrial balloon septostomy (BAS).

The BAS can be performed during a previous cardiac catheterisation session or immediately prior to implantation of the AFR device during the same session.

The device is fully retrievable and can be repositioned several times before release.

The procedure, which lasts about 40 minutes and is performed under general anaesthesia, consists of creating an inter-atrial communication, between the left and right atrium, by means of a hole in which the ring-shaped Atrial Flow Regulator is implanted; the latter ensures a diversion of the blood flow from the left to the right atrial cavities, with a relative reduction of the left atrial intracavitary pressure and indirectly of the pulmonary capillary pressure, whose increase can be responsible for dyspnoea on exertion.

The procedure is performed by trans-venous femoral puncture and after placing the wire inside the left superior pulmonary vein, the inter-atrial septum is dilated with a balloon of appropriate calibre (12-14 mm).

Subsequently, the delivery system, catheter, is advanced through which the AFR device is passed and finally progressively hooked up to the interatrial septum.

The data available to date from international studies show benefits in the post-operative course, including a significant reduction in symptoms and hospitalisations, associated with an improvement in symptoms and quality of life in treated patients with decompensation refractory to optimal medical therapy; it also makes it possible for patients to perform physical activity. The AFR device, once placed, does not need to be replaced.

It is a minimally invasive technique that is performed through the femoral vein, there is no surgical wound and pain symptoms are almost totally absent.

The patient returned home three days after the operation and does not need to undergo rehabilitation, but is advised to undergo periodic clinical-ecographic check-ups.

Shunt occlusion, stroke phenomena and right heart section overload conditions were not observed in the study.

AFR implantation reduces mortality in patients with heart failure, regardless of ejection fraction.