Interventional procedure consultation document

Thoracoscopic exclusion of the left atrial appendage (with or without other cardiac surgery) in atrial fibrillation for the prevention of thromboembolism

Closing the left atrial appendage of the heart to prevent stroke in people with non-valvular atrial fibrillation using keyhole surgery

Atrial fibrillation (AF) is the irregular and rapid beating of the upper two chambers of the heart (the atria). Typical symptoms can include palpitations, dizziness, shortness of breath and fatigue. In people with AF, blood clots often form in the left atrial appendage, which is a small sac off the left atrium. These clots can travel in the blood to the brain, where they may block the blood flow, causing a stroke. In this procedure, the mouth of the left atrial appendage is closed to prevent the migration of blood clots. This is carried out through small incisions in the chest, and using a video camera to help guide the procedure.

The National Institute for Health and Clinical Excellence (NICE) is examining thoracoscopic exclusion of the left atrial appendage (with or without other cardiac surgery) in atrial fibrillation for the prevention of thromboembolism and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about thoracoscopic exclusion of the left atrial appendage (with or without other cardiac surgery) in atrial fibrillation for the prevention of thromboembolism.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 22 March

Target date for publication of guidance: June 2011

1   Provisional recommendations

1.1  Current evidence on the safety and efficacy of thoracoscopic exclusion of the left atrial appendage (LAA) in atrial fibrillation (AF) for the prevention of thromboembolism as an adjunctive procedure to ablative techniques is inadequate in quantity and quality. Therefore this procedure should only be used as an adjunct to ablation with special arrangements for clinical governance, consent and audit or research.

1.2  Clinicians wishing to undertake thoracoscopic exclusion of the LAA in AF for the prevention of thromboembolism as an adjunct to ablation should take the following actions.

• Inform the clinical governance leads in their Trusts.
• Ensure that patients and their carers understand the uncertainty about the procedure’s safety and efficacy and provide them with clear written information. In addition, the use of NICE’s information for patients (‘Understanding NICE guidance’) is recommended (available from www.nice.org.uk/IPGXXXpublicinfo). [[details to be completed at publication]]
• Audit and review clinical outcomes of all patients having thoracoscopic exclusion of the LAA in AF for the prevention of thromboembolism as an adjunctive procedure to ablative techniques (see section 3.1).

1.3  Current evidence on the safety and efficacy of thoracoscopic exclusion of the LAA in AF for the prevention of thromboembolism when used in isolation is inadequate. Therefore this procedure should only be used in the context of research. Research studies should clearly define patient selection. They should report the cardiac rhythm achieved after surgery and also adverse events, particularly stroke and death, in both the short and longer term.

1.4  Patient selection should be carried out by a multidisciplinary team including a cardiac surgeon and other clinicians experienced in the management of patients with AF who are 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.

1.5  Thoracoscopic exclusion of the LAA in AF for the prevention of thromboembolism should be carried out only by cardiac surgeons with experience in thoracoscopic surgery and specific training in the procedure.

2   The procedure

2.1  Indications and current treatments

2.1.1  Atrial fibrillation 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 AF, thrombi largely develop in the LAA.

2.1.2  Patients with AF considered to be at high risk of thromboembolic stroke are usually treated with anticoagulation therapy. If a patient is unable to tolerate anticoagulation, then surgical obliteration of the LAA through percutaneous or open approaches may be offered.

2.2   Outline of the procedure

2.2.1  Thoracoscopic exclusion of the LAA in AF for the prevention of thromboembolism is usually carried out with the patient under general anaesthesia and often alongside other procedures such as radiofrequency or microwave ablation. Under thoracoscopic guidance the pericardium is opened and the atrial appendage excluded usually using staples. A chest drain may be placed until the lung is fully re-expanded. Postoperative transoesophageal echocardiography may be used to confirm exclusion of the LAA.

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, available at www.nice.org.uk/guidance/IP/857/overview

2.3   Efficacy

2.3.1  A case series of 100 patients treated by thoracoscopic LAA occlusion and epicardial radiofrequency ablation reported cardiovascular accidents (CVA) in 2% (2/88) of patients and transient ischaemic attack (TIA) in 2% (2/88) of patients over a mean follow-up of 23 months (88 patients followed-up).

2.3.2  A case series of 15 patients treated by the procedure alone reported an overall stroke rate of 4% per patient-year (95% confidence interval [CI] 1.0 to 16) (mean follow-up 42-months). Of these, 1 patient had a fatal stroke at 55-month follow-up.

2.3.3  The Specialist Advisers listed key efficacy outcomes as total occlusion of the LAA with endothelialisation and a demonstrable absence of residual appendage (on echocardiography); and prevention of sequelae of thrombus such as stroke or TIA.

2.4   Safety

2.4.1  Death was reported in 3% (3/100) of patients in the case series of 100 patients (not otherwise described).

2.4.2  Thoracotomy for postoperative bleeding from the LAA was reported in 1 patient in the case series of 15 patients. Intraoperative conversion to minithoracotomy to control bleeding was required in 3% (3/100) of patients in the case series of 100 patients.

2.4.3  The case series of 30 patients reported that 7% (2/30) of patients required drainage of  residual pneumothorax after removal of chest drains; and 1 patient required conversion to median sternotomy because of severe pleural adhesions.

2.4.4  The case series of 15 patients reported prolonged postoperative air leak and chronic pleuritic pain in 1 patient each. 

2.4.5  A case series of 81 patients reported acute cardiac dysfunction from subendocardial infarction (recovery within 12 days) in 1 patient.

2.4.6  The Specialist Advisers listed anecdotal adverse events as incomplete occlusion with residual appendage, and neuralgia from the thoracoscopic port sites.

2.5   Other comments

2.5.1  The Committee considered the prevention of stroke to be the most important efficacy outcome of this procedure. Evaluating its efficacy in preventing stroke is complicated by the concomitant use of procedures to ablate AF and the variable use of anticoagulants.

3   Further information

3.1  This guidance requires that clinicians undertaking the procedure as an adjunct to ablative techniques make special arrangements for audit. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.

3.2  For related NICE guidance see www.nice.org.uk

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

February 2011

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

_{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}