Left atrial appendage closure (Watchman): what it is and who it is for

Atrial fibrillation (AF) is an irregular and often rapid heartbeat in which the upper chambers of the heart do not contract effectively. NHS England explains that blood can pool and form clots; the left atrial appendage (LAA) is a small pouch in the wall of the left atrium, and over 90% of these clots form there. If a clot escapes into the circulation it can reach the brain and cause a disabling or fatal stroke, and AF is associated with a 5 times increased risk of stroke.

Left atrial appendage occlusion (LAAO), also called LAA closure, places a device at the mouth of the appendage to stop clots entering the bloodstream. Watchman is the name of one brand of device and people often use it to describe the procedure. The sources used here describe the procedure in general terms rather than any single product.

The usual way to reduce stroke risk in AF is oral anticoagulant (blood-thinning) medicine. NHS England says these are associated with the potential for severe bleeding and are unsuitable for people with a history of severe haemorrhage or high bleeding risk. LAAO is meant for people who cannot safely take them. Its policy sets out the people it will routinely fund: those with non-valvular AF and a CHA2DS2-VASc score of 2 or greater, together with physician-assessed contraindications to oral anticoagulants.

Examples include a history of major bleeding such as intracranial or major gastrointestinal bleeding in whom further anticoagulation is likely to cause a recurrent bleed, a high bleeding risk or inherited or acquired bleeding disorder discussed with a haematologist, and people who have had a stroke despite anticoagulant treatment.

The policy lists exclusions including life expectancy under 3 years, a clot visible in the appendage, valvular AF such as rheumatic mitral stenosis or a mechanical mitral valve, other reasons for lifelong anticoagulation, and people who are clinically suitable for oral anticoagulants. It states that LAAO should not be used as a salvage therapy and that the benefit accrues over time.

The NICE patient leaflet describes the procedure: the person is usually under general anaesthesia, a thin tube (catheter) is inserted into a vein at the top of the leg (the femoral vein) and guided into the left atrium, and a special device is moved up the catheter into place at the mouth of the appendage. Transoesophageal echocardiography, an ultrasound probe passed into the gullet, is used to confirm how well the device is working and its position.

NHS England says patients are admitted for the procedure on the day or the day before, may have echocardiography or CT beforehand, and will need an echocardiogram before discharge to check there is no significant pericardial effusion or device embolisation. Patients are likely to be referred via specialist services and will see a cardiologist to discuss the potential risks and benefits.

NICE says the procedure is complicated and that it can cause life-threatening complications in a small number of people, so it should only be carried out by doctors with specific training and in hospitals with facilities for emergency heart surgery. In the studies summarised by NICE for the patient leaflet, complications included blood collecting in the sac around the heart (pericardial effusion), which sometimes needed draining or emergency surgery, device embolisation (the device dislodging), damage to the femoral artery, a clot in the left atrium and a fractured delivery wire.

Because it is a relatively new procedure in comparison with blood-thinning drugs, NICE notes that there is not a lot of information about how well it works, how safe it is and which patients benefit most. The guidance asks that results are monitored and that patients understand the risks and agree to treatment. Ask your cardiologist for the current figures at your own hospital.

NHS England expects people to be assessed for single or dual antiplatelet therapy for a minimum of six months after implant, taking account of individual circumstances. The sources used here do not set out detailed recovery timelines, so follow the advice of the implanting team about activity, driving and when to seek help.

The NHS says there is currently no cure for atrial fibrillation, but treatment should help manage symptoms and lower the risk of complications such as blood clots, stroke and heart failure. LAAO addresses stroke risk; it does not treat the rhythm itself or its symptoms.

Call 999 straight away if you think you or someone else is having a stroke: face drooping, arm weakness, speech problems. The NHS says to call 999 even if the signs stop after a short time. Chest pain, severe breathlessness, fainting or sudden collapse after any heart procedure also need an emergency response.

In England the NHS commissions LAAO for the criteria above, so eligibility is decided by specialists using the policy. Because the NHS policy is for people who cannot take anticoagulants, people who can take them and prefer not to may find it is not offered on the NHS. If you are considering private care, it is reasonable to ask what the eligibility criteria are, which device is used, how many procedures the team has done and who will provide follow-up care.