Percutaneous occlusion of the left atrial appendage in non-valvular atrial fibrillation for the prevention of thromboembolism

# Guidance
This guidance replaces previous guidance on percutaneous occlusion of the left atrial appendage for atrial fibrillation (interventional procedure guidance 181).
Current evidence suggests that percutaneous occlusion of the left atrial appendage (LAA) is efficacious in reducing the risk of thromboembolic complications associated with non-valvular atrial fibrillation (AF). With regard to safety, there is a risk of life-threatening complications from the procedure, but the incidence of these is low. Therefore, this procedure may be used provided that normal arrangements are in place for clinical governance, consent and audit.
Patient selection should be carried out by a multidisciplinary team including a cardiologist and other appropriate clinicians experienced in the management of patients with AF at risk of stroke. Patients should be considered for alternative treatments to reduce the risk of thromboembolism associated with AF, and should be informed about these alternatives.
Percutaneous occlusion of the LAA is a technically challenging procedure which should only be carried out by clinicians with specific training and appropriate experience in the procedure.
This procedure should be carried out only in units with on-site cardiac surgery.
Any device-related adverse events resulting from the procedure should be reported to the Medicines and Healthcare products Regulatory Agency (MHRA).# The procedure

# Indications and current treatments
AF is the irregular and rapid beating of the atria. Patients with AF may be asymptomatic or may have symptoms such as fatigue, palpitations, chest pain, shortness of breath and fainting. They also have an increased risk of thromboembolic stroke. In non-rheumatic AF, thrombi largely develop in the LAA.
Patients with AF who are considered to be at high risk of thromboembolic stroke are often treated with warfarin anticoagulation therapy. Surgical intervention may involve obliteration of the LAA through an open or thoracoscopic approach.

# Outline of the procedure
Percutaneous occlusion of the LAA is usually carried out with the patient under general anaesthesia. Using fluoroscopic guidance, a catheter is advanced through the femoral vein into the right atrium and then into the left atrium via a transseptal puncture. The location of the LAA is confirmed and the size of the LAA orifice is established by transoesophageal echocardiography (TOE). An appropriately sized device is selected and deployed in the mouth of the LAA where it is expanded to fit the space.
The position and patency of the occlusion device may be confirmed postoperatively using echocardiographic imaging.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.

# Efficacy
A randomised controlled trial (RCT) of 707 patients treated by percutaneous closure of the LAA (n = 463) or warfarin (n = 244) reported 2.3 and 3.2 all-cause strokes respectively per 100 patient-years (rate ratio 0.71, credible interval  0.35 to 1.64).
A case series of 111 patients reported stroke in 2 patients at 173- and 215-day follow-up. TOE at 1 and 6 months revealed a stable device in both patients and no thrombogenic layer on the surface of the device.
Transient ischaemic attack was reported in 2 patients in the case series of 111 patients (not otherwise described).
The RCT of 707 patients treated by the procedure or warfarin reported successful closure in 88% (408/463) of patients randomised to the procedure.
The Specialist Advisers listed key efficacy outcomes as freedom from stroke, and other neurological and cardiac events.

# Safety
Cardiac tamponade requiring median sternotomy, pericardiocentesis and ligation of the LAA occurred 4 hours after the procedure in 1 patient in the case series of 111 patients. The patient later developed deep vein thrombosis and died 27 days after the procedure (attributed to cerebral haemorrhage associated with anticoagulation therapy).
Cardiac arrest 30 minutes after the procedure because of device embolisation was reported in 1 patient, who subsequently died, in a case series of 73 patients.
Device embolisation was reported in less than 1% (3/463) of patients in the RCT of 707 patients: 1 detected during the procedure, and 2 detected on TOE at 45-day follow-up (1 was removedpercutaneously and 2 underwent surgery; not otherwise described).
The case series of 73 patients reported that 1 implant required open heart surgery because the device was unstable.
Delivery wire fracture requiring surgical removal was reported in 1 patient in the case series of 75 patients.
The RCT of 707 patients reported pericardial effusion successfully treated surgically or with pericardiocentesis in 5% (22/463), pericardial effusion not requiring drainage in 2% (8/463), oesophageal tear in less than 1% (1/463) and procedure-related arrhythmia in less than 1% (1/463) of patients treated by percutaneous occlusion.
Perforation of the right femoral artery when accessing the right femoral vein and left atrial thrombus at the time of the procedure preventing the implantation of the device was reported in 1 patient each in the case series of 111 patients.
The Specialist Advisers considered theoretical adverse events to include the inability to recover an incorrectly positioned device by endovascular means, so requiring emergency surgery; and persistent atrial septal defect.

# Other comments
The Committee noted that the published evidence included different occlusion devices and were mindful that clinical outcomes may not necessarily be the same with all devices.
The Committee noted that new pharmacological products are in development for use in reducing the risk of thromboembolism associated with AF.# Further information
For related NICE guidance see our website.

# Information for patients
NICE has produced information on this procedure for patients and carers ('Understanding NICE guidance'). It explains the nature of the procedure and the guidance issued by NICE, and has been written with patient consent in mind.# About this guidance
NICE interventional procedure guidance makes recommendations on the safety and efficacy of the procedure. It does not cover whether or not the NHS should fund a procedure. Funding decisions are taken by local NHS bodies after considering the clinical effectiveness of the procedure and whether it represents value for money for the NHS. It is for healthcare professionals and people using the NHS in England, Wales, Scotland and Northern Ireland, and is endorsed by Healthcare Improvement Scotland for implementation by NHSScotland.
This guidance was developed using the NICE interventional procedure guidance process.
It updates and replaces NICE interventional procedure guidance 181.
It has been incorporated into the NICE pathway on stroke, along with other related guidance and products
We have produced a summary of this guidance for patients and carers. Information about the evidence it is based on is also available.
Changes since publication
January 2012: minor maintenance.
Your responsibility
This guidance represents the views of NICE and was arrived at after careful consideration of the available evidence. Healthcare professionals are expected to take it fully into account when exercising their clinical judgement. This guidance does not, however, override the individual responsibility of healthcare professionals to make appropriate decisions in the circumstances of the individual patient, in consultation with the patient and/or guardian or carer.
Implementation of this guidance is the responsibility of local commissioners and/or providers. Commissioners and providers are reminded that it is their responsibility to implement the guidance, in their local context, in light of their duties to avoid unlawful discrimination and to have regard to promoting equality of opportunity. Nothing in this guidance should be interpreted in a way which would be inconsistent with compliance with those duties.
Copyright
 National Institute for Health and Clinical Excellence 2010. All rights reserved. NICE copyright material can be downloaded for private research and study, and may be reproduced for educational and not-for-profit purposes. No reproduction by or for commercial organisations, or for commercial purposes, is allowed without the written permission of NICE.
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