Left atrial appendage closure: when might it be an alternative to anticoagulants?
Atrial fibrillation is the most common sustained cardiac arrhythmia. It can cause palpitations, tiredness or shortness of breath, although in some people it progresses for a time without any obvious symptoms. Its main risk, however, is not always apparent: it promotes the formation of blood clots within the heart and increases the likelihood of having a stroke.
To prevent this complication, standard treatment involves anticoagulant medication. These drugs significantly reduce the risk of thrombus formation, but cannot always be taken long-term. Some patients have experienced severe haemorrhages, are at high risk of bleeding, or have clinical conditions that make safe and continuous anticoagulation difficult.
In such cases, percutaneous closure of the left atrial appendage may be considered; this is a minimally invasive procedure designed to isolate a small structure within the heart where many of the clots associated with atrial fibrillation originate.
Dr Felipe Hernández, head of the Haemodynamics and Interventional Cardiology Unit at the Publio Cordón Memorial Hospital, explains that the procedure does not directly treat the arrhythmia:
‘Atrial appendage closure does not eliminate atrial fibrillation. Its aim is to reduce the risk of thrombi forming and being released from one of the structures most closely linked to stroke in these patients.’
It is not a general alternative to anticoagulants, nor is it a procedure indicated simply because a person prefers to stop taking medication. Its usefulness lies in carefully selected patients, particularly when it is difficult to balance stroke prevention against the risk of haemorrhage.
What is the left atrial appendage and why can it form blood clots?
The left atrial appendage is a small cavity located in the left atrium, one of the heart’s chambers. It forms part of the normal anatomy and has an irregular structure, with folds and recesses inside.
When the heart maintains a normal rhythm, the atria contract in a coordinated manner and help to pump the blood. In atrial fibrillation, this contraction becomes rapid, disorganised and less effective. Blood may then flow more slowly and become partially stagnant, particularly within the left atrial appendage.
This stagnation facilitates the formation of clots. If one of these clots breaks loose, it can leave the heart, reach the brain and block one of its arteries, causing an ischaemic stroke.
‘The anatomy of the atrial appendage is complex and varies from person to person,’ notes Dr Hernández. ‘When the atrium stops contracting properly, blood can become trapped inside it. The closure aims to exclude that cavity from the circulation and prevent a potential thrombus from reaching the rest of the body.’
To achieve this, a small device is placed at the entrance to the atrial appendage. This acts as a permanent barrier and, over time, becomes covered by the heart’s own tissue.
Anticoagulants remain the standard treatment
In most patients with atrial fibrillation and a high risk of stroke, oral anticoagulants remain the first-line preventive treatment.
The indication depends on factors such as age, high blood pressure, diabetes, heart failure, vascular disease, kidney function and a history of stroke. The risk of bleeding and the realistic possibility of safely continuing the treatment must also be assessed.
Having experienced a bleed does not automatically mean that anticoagulation should be discontinued or that the patient is a candidate for atrial appendage closure. It is first necessary to investigate the cause of the bleed, determine whether it can be corrected, and weigh up the risks of each alternative.
Dr Hernández emphasises that this decision requires a holistic approach: ‘It is not enough simply to know that a patient has experienced a bleed or is afraid to continue with anticoagulation. We must analyse their risk of stroke, the likelihood of them experiencing another bleed, and which strategy can offer them the greatest long-term safety.’
In which patients might closure be considered?
The procedure may primarily be considered in people with non-valvular atrial fibrillation, a significant risk of stroke and a contraindication, intolerance or relevant clinical difficulty in maintaining long-term oral anticoagulation.
Situations that may lead to consideration of closure include:
A history of severe or recurrent bleeding.
Intracranial or gastrointestinal bleeding with a significant risk of recurrence.
Diseases or injuries that considerably increase the risk of bleeding.
Embolic episodes despite appropriately indicated anticoagulation.
Clinical inability to maintain anticoagulant therapy with sufficient safety.
None of these circumstances, on its own, constitutes an automatic indication. It is also necessary to assess the anatomy of the anastomotic site, the patient’s general condition, the presence of other medical conditions, and the possibility of receiving antithrombotic medication during the initial post-implantation period.
‘Patient selection is probably the most important part of the process,’ says the specialist. ‘The procedure is of value when it addresses a specific clinical problem and when, after reviewing the alternatives, it offers a more favourable balance between stroke prevention and the risk of bleeding.’
In the most complex cases, the decision may require the coordinated involvement of clinical cardiology, interventional cardiology, electrophysiology, neurology, haematology or gastroenterology.
How is percutaneous closure performed?
The procedure is carried out in a haemodynamics and interventional cardiology suite, usually under deep sedation or general anaesthesia. Before the procedure, a transoesophageal echocardiogram or a cardiac computed tomography (CT) scan is usually carried out. These tests help to rule out the presence of blood clots, assess the shape and size of the atrial appendage, and plan the procedure.
Access is usually gained via a puncture in the femoral vein, located in the groin area. A catheter is inserted through this puncture and advanced into the right atrium. To reach the left atrium, the cardiologist carefully pierces the septum separating the two chambers.
Once the guidewire is positioned in the atrial appendage, its dimensions are checked again and a device is inserted which opens up and adapts to the opening. Before fully deploying it, the team confirms its position, stability and the degree of sealing achieved.
“It is not open-heart surgery,” explains Dr Hernández. “We access the heart via the femoral vein and carry out the entire procedure using catheters, guided by fluoroscopy and echocardiography. These imaging techniques allow us to work with precision and verify the result before completing the procedure.”
The anatomy of the atrial appendage can vary significantly between patients. For this reason, image-guided planning is not a secondary consideration, but an essential part of the procedure. It enables us to select the most appropriate type and size of device and to anticipate any potential technical difficulties.
What happens after the procedure?
Following the procedure, the patient remains under observation for 24 hours provided their recovery is going well, although the duration depends on their general condition and any associated medical conditions.
During the first few weeks or months, it may be necessary to continue taking anticoagulants, antiplatelet agents or a combination tailored to each individual case. This medication protects the patient whilst the device gradually integrates into the heart and becomes covered by tissue.
For this reason, the closure does not allow for the immediate and automatic discontinuation of all antithrombotic treatment. The treatment regimen should only be modified on medical advice.
Follow-up care includes a clinical assessment and, usually, an imaging scan. Transoesophageal echocardiography or cardiac CT is used to check that the device remains correctly positioned, that the atrial appendage is properly sealed and that no thrombi have formed on its surface.
“The procedure does not end with the implantation,” explains Dr Hernández. “Treatment during the first few weeks and subsequent check-ups are essential to confirm that the device has integrated correctly and to decide when medication can be adjusted.”
What benefits can it offer?
In appropriately selected patients, atrial appendage closure can reduce the risk of atrial fibrillation-related blood clots reaching the cerebral circulation. Its main benefit lies in those individuals who require protection against stroke, but for whom maintaining anticoagulation for years poses a significant risk or clinical challenge.
The available scientific evidence shows that, in certain patient profiles, closure can offer protection comparable to oral anticoagulation, although the two strategies are not equivalent for all patients.
One of the most significant studies is PRAGUE-17, which compared atrial appendage closure with direct oral anticoagulants in people with atrial fibrillation and a high risk of both stroke and bleeding. After four years’ follow-up, patients treated with closure had overall outcomes comparable to those who continued on anticoagulants. Furthermore, a reduction in clinically relevant bleeding events unrelated to the procedure itself was observed.
In simple terms, the study suggests that, in particularly complex and carefully selected patients, closure can provide adequate protection against embolic events whilst avoiding some of the cumulative bleeding risk associated with long-term anticoagulant therapy.
The OPTION trial analysed a more specific scenario: patients with atrial fibrillation who had undergone ablation and who continued to be at high risk of stroke. At three years, those who underwent atrial appendage closure experienced fewer major or clinically relevant haemorrhages than those who continued with anticoagulation, without any observed loss of protection against stroke or systemic embolism.
This study is particularly interesting because it serves as a reminder that effective ablation does not necessarily eliminate the risk of embolism. Even if the patient perceives an improvement or maintains a controlled heart rhythm, the decision to continue or modify stroke prevention depends on their risk profile and not solely on the apparent disappearance of the arrhythmia.
The differences between the available devices have also been investigated. The Amulet IDE trial showed that two of the most widely used systems could provide adequate prevention, albeit with differences in their ability to adapt to and seal the atrial appendage. Rather than identifying a universally superior device, its results reinforce the importance of first assessing the patient’s anatomy and selecting the most appropriate implant for each individual.
These results do not allow us to conclude that closure is preferable to anticoagulants in all people with atrial fibrillation. The studies were carried out in selected populations, with specific risks and medical histories. Their true value lies in helping the medical team identify in which patients the procedure may offer a more favourable balance of benefits and risks.
What risks should be taken into account?
Percutaneous atrial appendage closure is a minimally invasive procedure that is routinely performed with good results in centres and by experienced teams. Like any cardiac catheterisation procedure, it is not entirely risk-free, although the likelihood and severity of risks depend on the patient’s general health, their anatomy, any associated conditions and the specific complexity of each case.
Complications may arise during the procedure or in the post-procedure period, such as bleeding at the access site, fluid build-up around the heart, thrombus formation on the device, incomplete closure or displacement of the implant, amongst others. Serious complications are rare, but must be explained and assessed before the procedure is indicated.
Planning using echocardiography or cardiac CT, appropriate device selection and the team’s experience all help to reduce these risks. It is also essential to adhere to temporary antithrombotic therapy and to undergo follow-up imaging, as part of the procedure’s safety depends on this follow-up.
Therefore, the risk of the procedure should not be analysed in isolation. It must be weighed against the risk that the same individual would face of suffering a stroke, a further haemorrhage, or a complication arising from continuing or discontinuing anticoagulation.
A personalised decision
Closure of the left atrial appendage should not be viewed simply as a way of stopping anticoagulant therapy. Its purpose is to provide a stroke prevention strategy for selected patients in whom prolonged anticoagulation presents a significant clinical challenge or a haemorrhagic risk that is difficult to accept.
The decision must take into account the individual risk of stroke, a history of bleeding, the cause of previous bleeds, kidney function, associated conditions, the anatomy of the atrial appendage, treatments already used and the possibility of continuing medication temporarily after the procedure.
The patient’s preferences must also be taken into account, once the benefits, limitations and risks of each option have been clearly explained.
“Technology allows us to offer options that were not available a few years ago, but it is no substitute for clinical judgement,” concludes Dr Hernández. “The true value of the procedure lies in selecting the right patient, planning precisely and ensuring careful follow-up both before and after the procedure.”
When the indication is appropriate and the procedure is performed by an experienced team, percutaneous closure of the left atrial appendage can represent an important alternative for preventing stroke in patients with atrial fibrillation who cannot safely maintain long-term oral anticoagulation.
Frequently asked questions
Does appendage closure cure atrial fibrillation?
No. The procedure does not eliminate the arrhythmia, nor is it intended to directly control palpitations or heart rate. Its aim is to reduce the risk of thrombus formation and release from the left atrial appendage.
Does it allow anticoagulants to be stopped immediately?
Not necessarily. It is usually necessary to continue taking anticoagulants, antiplatelet agents or a combination tailored to each patient for a period of time. The decision to withdraw or modify treatment must be made by the medical team after verifying that the device has been correctly implanted.
Who can benefit from the procedure?
Primarily, patients with atrial fibrillation, a significant risk of stroke and significant clinical difficulties in maintaining long-term anticoagulation. The indication requires an individual assessment and does not depend solely on a preference to stop taking medication.
Is it open-heart surgery?
No. It is performed using catheters, usually inserted via a vein in the groin. It does not require opening the chest, although it does require a specialised procedure, cardiac imaging guidance and subsequent follow-up.
What follow-up is required?
The patient must attend regular cardiology check-ups and undergo the recommended imaging tests to check the position and integration of the device. The closure procedure does not eliminate the need to continue treating other cardiovascular risk factors, such as high blood pressure, diabetes or heart failure.
The information in this article is provided for general awareness and does not replace an individualised medical assessment.
