Interventional procedure consultation document - radiofrequency ablation for atrial fibrillation in association with other cardiac surgery

NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Radiofrequency ablation for atrial fibrillation in association with other cardiac surgery

The National Institute for Clinical Excellence is examining radiofrequency ablation for atrial fibrillation in association with other cardiac surgery and will publish guidance on its safety and efficacy to the NHS in England, Wales and Scotland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about radiofrequency ablation for atrial fibrillation in association with other cardiac surgery.

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 preliminary recommendation
  • the identification of factual inaccuracies
  • additional relevant evidence.

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

The process that the Institute 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  • The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.

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

Closing date for comments: 26 January 2005

Target date for publication of guidance: 27 April 2005


Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.


1 Provisional recommendations
1.1

Current evidence on the safety and efficacy of radiofrequency ablation (RFA) for atrial fibrillation in association with other cardiac surgery appears adequate to support the use of this procedure provided that the normal arrangements are in place for consent, audit and clinical governance.

1.2

Patient selection and follow-up should be carried out by a multidisciplinary team. Cardiac surgeons wishing to use this procedure should be specifically trained in the use of radiofrequency equipment.



2 The procedure
2.1 Indications
2.1.1

Atrial fibrillation is the irregular and rapid beating of the upper two chambers of the heart (the atria). It may be classified as paroxysmal, persistent or permanent. It is the most common type of arrhythmia and the incidence increases markedly with age. Patients with atrial fibrillation may be asymptomatic or they may have symptoms such as palpitations, dizziness and breathlessness. They also have an increased risk of stroke as a result of blood clots forming in the left atrium and then embolising to the brain.

2.1.2 Although atrial fibrillation may occur in the absence of other heart disease, it is particularly common in patients with mitral valve disease.
2.1.3

Conservative treatments include medication, electrical cardioversion to control the heart rhythm, and anticoagulants to prevent blood clots forming. The alternative surgical approach, known as the Cox maze procedure, involves making small, strategically placed incisions in both atria to isolate and stop the abnormal electrical impulses.

2.2 Outline of the procedure
2.2.1

Radiofrequency ablation (RFA) for atrial fibrillation is typically carried out in patients undergoing concomitant open heart surgery, including mitral valve replacement or repair. The procedure uses thermal damage rather than incisions to block impulse conduction. The heat generated coagulates the heart tissue, forming linear scars or lesions that disrupt the transmission of the abnormal electrical impulses. The procedure may be carried out on both atria or on the left atrium only. It can be performed from within or outside the atrium.

2.3 Efficacy
2.3.1

In one small randomised controlled trial, 82% (9/11) of patients treated with atrial RFA and a mitral valve replacement were in sinus rhythm at 12 months, compared with 21% (3/14) of patients treated with a mitral valve replacement alone (p < 0.05). One non-randomised controlled trial reported that 81% (83/102) of patients treated with atrial RFA and cardiac surgery were in sinus rhythm at a mean follow-up of 12.5 months, compared with 11% (3/27) of patients who had cardiac surgery without RFA (p < 0.0001). For more details, refer to the sources of evidence.

2.3.2

The Specialist Advisors considered this procedure to be a variation on the Cox maze technique.

2.4 Safety
2.4.1

As this procedure is performed during open heart surgery, it is difficult to differentiate the complications that relate specifically to RFA.

2.4.2

In-hospital mortality was reported by six studies, and ranged from 0.8% (1/132) to 8% (3/40). In a study of 103 patients, 1 death was reported to be the result of an oesophageal perforation caused by RFA. Another study noted that none of the peri-operative deaths was considered to be related to the use of RFA.

2.4.3 Two studies reported that 2% (3/132) and 8% (18/234) of patients needed re-exploration for bleeding. Two studies reported that 0.8% (2/234) and 8% (16/200) of patients required re-operation. Other less common complications included the need for an intra-aortic balloon pump, sternal wound infection, stroke, atrio oesophageal perforation and left atrial thrombus. For more details, refer to the sources of evidence.
2.4.4 The Specialist Advisors listed the potential adverse effects of RFA as oesophageal injury, heart block, perforation of the heart, and coronary artery damage.
2.5 Other comments
2.5.1 The Committee noted that most of the data were on patients having mitral valve surgery. There was only limited evidence on the efficacy of RFA when performed with other procedures such as coronary artery bypass grafting.
2.5.2 The Committee noted that this procedure appears to be more efficacious in patients whose atrial fibrillation has been of short duration (less than 1 year).
2.5.3 The Committee noted that there are variations in technique and radiofrequency energy settings used for this procedure. They also noted that it may be difficult to determine when full-thickness ablation has been achieved.
3 Further Information
3.1 The Institute is preparing guidance on microwave ablation for atrial fibrillation (www.nice.org.uk/ip_266) and cryoablation for atrial fibrillation (www.nice.org.uk/ip_271). The Institute is also currently developing a guideline for the diagnosis and treatment of atrial fibrillation. For further information visit the NICE website at www.nice.org.uk.
3.2 The Institute has recently been notified of radiofrequency catheter ablation for atrial fibrillation, and more information can be found on the website (www.nice.org.uk/ip_300).


Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
January, 2005

Appendix: Sources of evidence

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

Interventional procedure overview of radiofrequency ablation for atrial fibrillation in association with other cardiac surgery, July 2004

Available from: www.nice.org.uk/245overview

This page was last updated: 03 February 2011