Left atrial appendage occlusion

Left atrial appendage occlusion is a procedure that closes off a small pouch in your heart, called the left atrial appendage, where blood clots linked to atrial fibrillation (AF) most often form. It's an alternative to long-term blood-thinning medication for people whose risk of bleeding on these drugs is too high.

What conditions does it treat?

This procedure is for people with atrial fibrillation (AF), an irregular and often fast heart rhythm. AF affects an estimated 1.5% of the UK population, rising to around 6.5% of people over 65 and 28.5% of those over 85.

With AF, blood isn't squeezed out of the heart's upper left chamber as effectively as normal, so it can collect and pool in the left atrial appendage, a small pouch off to the side, and clot there. If a clot escapes and travels to the brain, it causes a stroke.

The standard way to reduce this risk is blood-thinning medication (anticoagulants such as warfarin, apixaban, rivaroxaban, dabigatran or edoxaban). This procedure is instead offered to people who can't take these medications long-term, usually because of a high risk of bleeding, for example a previous bleed in the stomach or bowel, or a stroke caused by bleeding in the brain.

What are the benefits?

It doesn't remove your risk of stroke entirely, but appears to be about as effective as blood-thinning medication, without the bleeding risk that comes with it.

• You may be able to stop taking blood thinners in the long run, once your appendage has fully sealed.
• Your heart carries on working normally once the appendage is closed off.
• It can sometimes be combined with open heart surgery you're already having for another reason.
• It doesn't appear to harm quality of life, and some people report less anxiety afterwards.

Are there different types of device?

• Devices that plug the appendage's opening, such as Watchman or Amulet, the two most commonly used in the UK, or WaveCrest.
• Devices that clamp the base of the appendage shut, such as AtriClip.
• Devices that tie the appendage closed with a band or loop, such as Lariat or Sierra.
• Surgical removal or clipping of the appendage, usually done at the same time as open. heart surgery you're already having for another reason, such as valve or coronary artery surgery.

What happens before the procedure?

• Your case is usually discussed at a multidisciplinary team meeting, to explore whether this procedure, rather than continuing with blood-thinning medication, is right for you.
• Imaging of your left atrial appendage, typically an ultrasound scan through your food pipe and sometimes a CT scan, since the appendage's shape varies a lot between people and this helps your team choose the right size and type of device.
• Continuing to take blood-thinning medication in the run-up to your procedure; if you're unable to take this at all, the procedure may not be possible, and an alternative approach will be discussed with you.
• Instructions on when to stop eating and drinking beforehand.

What happens during the procedure?

1. You're given a general anaesthetic.
2. Once you're asleep, an ultrasound probe is passed through your mouth into your food pipe, to check your left atrium and left atrial appendage for any existing clots. If a clot is found, the procedure is postponed until it has cleared with blood-thinning medication.
3. If there's no clot, two small tubes are placed into veins near your groin.
4. A catheter carrying the closure device is passed through one of these tubes, into the right side of your heart, then through a small, deliberately made hole into the left side.
5. Using the ultrasound probe to guide them, your doctor positions the device permanently in your left atrial appendage, sealing its opening.
6. The catheter and tubes are then removed.

What does recovery look like?

In hospital

Afterwards, you'll have an echocardiogram and be monitored by the clinical team. Most people stay in hospital for one night before being discharged home, though some need a longer stay of 2 nights or more.

At home

You'll usually need to keep taking blood-thinning medication for a period afterwards, while your body grows a smooth lining over the device. The exact medications and timing may vary, but it commonly continues for around 6 months in total, sometimes with a switch to a different combination of drugs partway through.

You'll have a follow-up scan, using the same ultrasound technique from your procedure, to check your left atrial appendage is now sealed. Timing for this varies, with some teams scanning within about 6 weeks and others closer to 3 months. If it isn't fully sealed yet, you'll continue the blood-thinning medication and have a further scan a few months later. Once your team is satisfied that it's sealed, you'll move onto less frequent, usually annual, check-ups.

What are the risks and complications?

• Stroke
• Damage to the veins or arteries in your groin, where the tubes are inserted
• Bleeding around the heart needing urgent drainage, sometimes with a blood transfusion
• Risk of needing cardiac surgery
• Risk of the device moving out of place, needing cardiac surgery to correct it
• Risk of death
• Other possible complications include a problem with the device itself, a reaction to the anaesthetic, infection, an abnormal heart rhythm, or fluid building up around the heart

Overall, around 1 in 20 people have a major complication, such as death, stroke, a major bleed or a heart attack, while still in hospital.