• New Zealand Guidelines Group (NZGG). The management of people with atrial fibrillation and flutter. Wellington (NZ): New Zealand Guidelines Group (NZGG); 2005 May. 177 p. [422 references]

This is the current release of the guideline.

Atrial fibrillation and atrial flutter

Evaluation
Management
Risk Assessment
Treatment

Cardiology
Family Practice
Internal Medicine
Pulmonary Medicine

Physicians

• To provide an evidence-based summary of effective practice in the assessment and management of atrial fibrillation (AF) and atrial flutter (AFL) in New Zealand
• To assist and provide guidance to general practitioners and specialists involved in the care of people with atrial fibrillation and atrial flutter, including general physicians, cardiologists, neurologists, geriatricians, stroke specialists, haematologists, and emergency room staff

Persons with atrial fibrillation or atrial flutter

Note: This guideline specifically excludes consideration of atrial fibrillation occurring after cardiac and other surgery.

Clinical Evaluation

1. Patient history
2. Clinical examination
3. Electrocardiograph (ECG)
4. Transthoracic echocardiogram (TTE)
5. Blood tests (thyroid function (with thyroid stimulating hormone [TSH]), renal function (creatinine), International Normalized Ratio (INR) (pre-warfarin)
6. Additional testing, as indicated: chest x-ray, exercise tolerance test, 24-hour Holter monitoring, electrophysiological testing, transoesophageal echocardiogram (TOE)

Management and Treatment

1. Prevention of thromboembolism
   • Thromboembolic risk assessment
   • Antithrombotic treatment (warfarin, aspirin)
2. Rate control (non-acute and acute)
   • Beta-blockers (atenolol, carvedilol, metoprolol, nadolol, propranolol, esmolol)
   • Other pharmacological agents (verapamil, diltiazem, digoxin, amiodarone)
   • Combined atrioventricular (AV) nodal ablation and pacing
3. Rhythm control
   • Electrical cardioversion
   • Pharmacological cardioversion (amiodarone, flecainide, propafenone)
   • Pharmacological maintenance of sinus rhythm (amiodarone, disopyramide, flecainide, propafenone and sotalol)
   • Nonpharmacological maintenance of sinus rhythm (pacemaker implantation, atrial defibrillator implantation, ablation including catheter ablation in and around the pulmonary veins, catheter ablation of atrial flutter [AFL] and accessory pathways, and surgical ablation)

• Rate and rhythm control
• Symptom control
• Morbidity and mortality
• Quality of life
• Risk of thromboembolic complications
• Adverse events associated with treatment

Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases

Not stated

Weighting According to a Rating Scheme (Scheme Given)

Levels of Evidence

+ Assigned when all or most of the criteria are met

~ Assigned when some of the criteria are met and where unmet criteria are not likely to affect the validity, magnitude, or applicability of the results markedly

x Assigned when few or none of the criteria are met

Review of Published Meta-Analyses
Systematic Review with Evidence Tables

Expert Consensus

A multidisciplinary group composed of professionals and a consumer representative was convened as the Guideline Development Team in early 2003. Team members were nominated by a variety of stakeholders including the Royal New Zealand College of General Practitioners (RNZCGP), the Cardiac Society of Australia and New Zealand, the Stroke Foundation of New Zealand, Pathology Associates, the Neurology Association, and the Mäori Cardiovascular Group.

Two face-to-face meetings were held in Auckland during 2003. The goal of the first meeting, held at the end of June, was to train members of the team in the processes of guideline development, to identify relevant clinical questions, and to make decisions about the scope of the guideline. Prior to the meeting, a large guideline published in 2001 was identified, entitled ACC/AHA/ESC Guidelines for the Management of People with Atrial Fibrillation, which had been developed jointly by the American College of Cardiology (ACC), the American Heart Association (AHA) and the European Society of Cardiology (ESC).

At this first meeting, the Guideline Development Team agreed to adapt this guideline for the New Zealand setting and permission was granted by the American College of Cardiology. The team agreed to accept in principle the major recommendations, where appropriate, and to update the 2001 ACC/AHA/ESC guideline by searching for more recent evidence and considering the impact of this on the 2001 recommendations. The NZGG grading system (see "Rating Scheme for the Strength of the Recommendations") was used rather than the grading system used in the ACC/AHA/ESC 2001 guideline. Consideration was also given to the relevance of the guideline to the local setting as part of the adaptation process. Other relevant guidelines for atrial fibrillation (AF) located by a preliminary search were used in the development of this guideline.

The second meeting of the Guideline Development Team, held at the end of November 2003, developed graded recommendations based on the compiled evidence tables, using the Considered Judgment process. Algorithms that linked to the recommendations were also developed.

The guideline text was written by the project team with contributions from members of the Guideline Development Team, based upon the agreed recommendations from the second meeting.

Levels of Recommendation

A - The recommendation is supported by GOOD evidence (where there is a number of studies that are valid, consistent, applicable, and clinically relevant)

B - The recommendation is supported by FAIR evidence (based on studies that are valid, but there are some concerns about the volume, consistency, applicability, and clinical relevance of the evidence that may cause some uncertainty but are not likely to be overturned by other evidence)

C - The recommendation is supported by EXPERT OPINION only (from external opinion, published or unpublished, e.g., consensus guidelines).

I - No recommendation can be made. The evidence is insufficient (either lacking, of poor quality, or conflicting and the balance of benefits and harms cannot be determined).

GPP - Where no evidence is available, best practice recommendations are made based on the experience of the Guideline Development Team, or feedback from consultation within New Zealand.

The projected increase in the prevalence of atrial fibrillation (AF) will add greatly to health care costs in New Zealand. Although few specific data were available to document current management of AF in New Zealand, there is clear evidence of variation in the use of drug treatments and underutilisation of anticoagulation to prevent stroke. This gap between current and optimal management of AF will add to health care costs.

Other Western countries have documented an increase in the proportion of total health expenditure for AF in recent years. In 1995, the direct cost of health care for people with AF in the United Kingdom was 0.62% of the total National Health Service (NHS) expenditure. This included hospitalisations, drug prescriptions, and long-term nursing home care after hospital admission, with approximately 50% of this cost being for hospitalisation. By the year 2000, the direct cost of health care for people with AF had risen to 0.97% of total NHS expenditure, based on 1995 figures.

Improved access to echocardiography is urgently needed. Publicly-funded access to echocardiography services in a reasonable time frame is currently variable across New Zealand and in some regions non-existent. Consistent with the National Heart Foundation of New Zealand's consensus guidelines for the management of heart failure, timely access to echocardiography is important for optimal management and outcomes to occur.

The underutilisation of anticoagulant therapy to prevent stroke contributes significantly to health care costs. It has been estimated that the life-time cost of one stroke is approximately NZ$50,000. Although estimates of the use of anticoagulation in people with AF in New Zealand vary, the highest estimate suggests that approximately 32% of people with AF take warfarin therapy. The evidence suggests that the majority of people with AF would benefit from anticoagulant treatment. If the proportion of people with AF taking anticoagulant therapy increased from 32 to 50%, this could prevent approximately 200 strokes per year in New Zealand, with a cost saving of around NZ$10 million per year.

A strategy of anticoagulation and rate control is considered appropriate for the majority of people with AF. This guideline, as well as recent data, suggests that there should be a reduced emphasis on rhythm control, except in younger symptomatic people (see Chapter 5 entitled "Management Principles" in the original guideline document). This change is likely to reduce hospital admissions as well as the adverse effects of antiarrhythmic therapy, which should result in further savings.

A full economic analysis has not been undertaken in this guideline, but the implementation of its recommendations has the potential to improve health outcomes for people and rationalise health expenditure. It is hoped that the implementation of these recommendations will result in a reduction in total expenditure for AF and its consequences.

External Peer Review
Internal Peer Review

In early 2004, individual chapters were sent out to the whole group for comment and feedback, and the full document was sent out for peer review to relevant stakeholders in August/September 2004. The guideline was subsequently circulated for final sign-off and published in May 2005.

Definitions for the Levels of Evidence and Grades of Recommendation (A-C, I, and Good Practice Points [GPP]) are given at the end of the "Major Recommendations" field. Where no evidence is available, best practice recommendations are made based on the experience of the Guideline Development Team.

Clinical Evaluation

C - All people presenting with atrial fibrillation/atrial flutter (AF/AFL) for the first time should have the following investigations:

• History and clinical examination
• Electrocardiograph (ECG)
• Transthoracic echocardiogram (TTE)
• Blood tests -- thyroid function (with thyroid stimulating hormone [TSH]), renal function (creatinine), International Normalized Ratio (INR, [pre-warfarin]).

C - Additional testing may also be necessary in selected cases.

• Chest x-ray if clinical findings suggest pulmonary abnormality
• Exercise tolerance test
• 24-hour Holter monitoring
• Electrophysiological testing
• Transoesophageal echocardiogram (TOE)

GPP - Improved access to TTE throughout New Zealand is recommended.

Prevention of Thromboembolism

A - All people with AF/AFL require thromboembolic risk assessment, irrespective of the current rhythm. The majority of people with AF/AFL require anticoagulation to reduce their risk of stroke.

A - Antithrombotic treatment (oral anticoagulation or aspirin) should be administered to all people with AF/AFL, except those with lone AF (people <60 years with no hypertension or heart disease), to reduce the risk of thromboembolic events.

• People with AF/AFL at HIGH or VERY HIGH risk of stroke should receive long-term anticoagulant treatment with adjusted-dose warfarin aiming for an INR between 2.0 and 3.0 (target 2.5), unless there are clear contraindications. (A)
• People with AF/AFL at INTERMEDIATE risk of stroke should discuss their individual risks, the potential benefits, and their preferences regarding anticoagulant or aspirin treatment, with their doctors. (C)
• People with AF/AFL at LOW risk of stroke or who have a contraindication to warfarin should receive aspirin. There is insufficient evidence to recommend a specific dose (some experts recommend 300 mg aspirin daily). (B)
• People with previous AF, or paroxysmal AF (PAF) who have converted to sinus rhythm, remain at increased thromboembolic risk. They should be assessed for thromboembolic risk and treated with warfarin or aspirin as described above. (B)

A - Anticoagulation should be started in every person with AF/AFL and ischaemic stroke or transient ischaemic attack (TIA) unless contraindicated, once intracranial haemorrhage has been excluded.

GPP - The risk of bleeding needs to be assessed in all people with AF/AFL being considered for anticoagulant treatment and periodically reassessed.

Rate Control

A - Rate control is the recommended strategy for the majority of people with AF/AFL.

In the non-acute situation:

• Beta-blockers (particularly atenolol, carvedilol, metoprolol, nadolol, and propranolol), verapamil, diltiazem, and digoxin are effective rate-control agents, although digoxin is not effective during exercise. (A)
• A combination of rate-control agents is sometimes required to achieve adequate rate control, but the combination of a beta-blocker with verapamil should be used with considerable caution. (C)

In acutely symptomatic people with rapid AF/AFL, consider use of the following intravenous (IV) rate-control agents, which have proven effective in haemodynamically stable people:

• Esmolol (very short-acting), metoprolol, propranolol, diltiazem or verapamil (A)
• Amiodarone, digoxin (B)

GPP - Note: Atenolol intravenous (IV) is not currently available in New Zealand. The choice of medication should be individualised.

B - Sotalol should NOT be used solely for rate control because it is associated with a higher incidence of life-threatening ventricular arrhythmias (particularly torsades de pointes).

Combined atrioventricular (AV) nodal ablation and pacing should be considered for people with:

• Permanent AF/AFL in whom ventricular rate remains poorly controlled despite optimal tolerated medical therapy and either persistent symptoms or left ventricular dysfunction (LVD) (A)
• AF/AFL and a rate-related cardiomyopathy that is unresponsive to drug therapy (A)
• Paroxysmal AF/AFL, if their symptoms are particularly troublesome (C)

GPP - The management of all people with AF/AFL should include assessment and control of ventricular rate both at rest and during exercise. Rate control should be periodically reassessed.

Rhythm Control

C - People who have significant haemodynamic compromise or rate-related angina, myocardial ischaemia, or acute pulmonary oedema, as a result of rapid AF/AFL, should be cardioverted immediately where possible.

C - Electrical cardioversion is the treatment of choice for people with pre-excited AF (Wolff-Parkinson-White [WPW] syndrome) with any haemodynamic compromise. If the person is stable and pre-excitation is intermittent or rates are slower, pharmacological cardioversion (see Section 8.1.4 of the original guideline document entitled "Pharmacological Cardioversion") can be considered, but AV nodal blockers (beta-blockers, non-dihydropyridine calcium channel blockers, and digoxin) must be avoided.

C - People with unacceptable arrhythmia-related symptoms should be considered for a rhythm-control approach.

B - If a rhythm control strategy is chosen for people who are not anticoagulated, they should be cardioverted within 48 hours of onset. If they cannot be cardioverted within 48 hours of onset, then they should have either:

• A therapeutic INR (2.0 to 3.0, target 2.5) for at least 3 weeks, OR
• A transoesophageal echocardiogram to exclude atrial thrombi before cardioversion

C - People with AF/AFL who should NOT receive electrical cardioversion include those with:

• Serum potassium outside the normal range
• A contraindication to, or intolerance of, conscious sedation or anaesthesia (or anticoagulation, if this is to be given)
• Digoxin toxicity
• Advanced conduction system disease
• Suboptimal anticoagulation
• Intermittent AF, with periods of sinus rhythm over the immediate precardioversion period
• A history of clear early relapse, despite optimal pharmacological maintenance therapy

B - Appropriate shock energy levels to achieve electrical cardioversion are:

• Monophasic waveform -- initially 200 J, then 300 to 360 J
• Biphasic waveform -- initially 100 or 120 J, then 150 to 200 J (for AFL, initially 10 to 50 J)

If shocks are initiated at these energy levels, most people are likely to require only one or two shocks to achieve sinus rhythm.

A - Consider the following agents for pharmacological cardioversion:

• Amiodarone (IV or oral)
• Flecainide (IV or oral)
• Propafenone (IV or oral)

Note: The pharmacological agents capable of very rapid cardioversion (dofetilide, ibutilide, and procainamide) are not currently available in New Zealand.

A - Flecainide or propafenone therapy usually results in more rapid cardioversion than amiodarone therapy, but should be avoided if there is clinical suspicion of structural heart disease (e.g., past myocardial infarction, coronary disease, LVD, severe left ventricular hypertrophy [LVH]). In these cases amiodarone is the preferred agent for pharmacological cardioversion.

A - Sotalol is not recommended for cardioversion because it is ineffective in this setting.

B - Consider amiodarone (e.g., 400 mg/day) pretreatment (3 to 4 weeks) for people with persistent AF who are awaiting an elective electrical cardioversion procedure, as long as they have already received at least 3 weeks of therapeutic warfarin.

A - Amiodarone, disopyramide, flecainide, propafenone, and sotalol are recommended for the pharmacological maintenance of sinus rhythm.

C - The choice of antiarrhythmic agent for maintenance of sinus rhythm should be made on the basis of safety considerations, such as contraindications in certain subgroups, and the potential for cardiac and non-cardiac side effects.

Highly selected people may be considered for nonpharmacological maintenance of sinus rhythm. These treatments include:

• Pacemaker implantation (B)
• Atrial defibrillator implantation (C)
• Ablation, which includes catheter ablation in and around the pulmonary veins, catheter ablation of AFL (see Section 9.4 of the original guideline document, entitled "Atrial flutter") and accessory pathways, and surgical ablation (C)

GPP - People experiencing unexplained breathlessness while taking amiodarone should be promptly referred for evaluation, as amiodarone may cause pulmonary fibrosis.

Heart Failure

The management of AF/AFL in people with overt heart failure differs in important ways from that in other people (see Section 9.3 of the original guideline document titled "Recent or acute congestive heart failure").

Definitions:

Levels of Evidence

+ Assigned when all or most of the criteria are met

~ Assigned when some of the criteria are met and where unmet criteria are not likely to markedly affect the validity, magnitude, or applicability of the results

x Assigned when few or none of the criteria are met

Grades of Recommendations

A - The recommendation is supported by GOOD evidence (where there is a number of studies that are valid, consistent, applicable, and clinically relevant)

B - The recommendation is supported by FAIR evidence (based on studies that are valid, but there are some concerns about the volume, consistency, applicability, and clinical relevance of the evidence that may cause some uncertainty but are not likely to be overturned by other evidence)

C - The recommendation is supported by EXPERT OPINION only (from external opinion, published or unpublished, e.g., consensus guidelines).

I - No recommendation can be made. The evidence is insufficient (either lacking, of poor quality, or conflicting and the balance of benefits and harms cannot be determined).

GPP - Where no evidence is available, best practice recommendations are made based on the experience of the Guideline Development Team, or feedback from consultation within New Zealand.

Clinical algorithms are provided in the original guideline document for:

• First Episode of Atrial Fibrillation
• Second or Subsequent Episode of Atrial Fibrillation
• Antiarrhythmic Therapy to Maintain Sinus Rhythm
• Direct Current Cardioversion for Persistent Atrial Fibrillation

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

Appropriate treatment and management of atrial fibrillation and atrial flutter, resulting in an improvement in patient quality of life and decrease in the incidence of associated thromboembolic events

• Side effects of therapy, including complications of anticoagulant and antiarrhythmic drugs and electrical cardioversion. The main risk of anticoagulant therapy is bleeding, and the main risk of antiarrhythmic therapy is proarrhythmia.
• People experiencing unexplained breathlessness while taking amiodarone should be promptly referred for evaluation, as amiodarone may cause pulmonary fibrosis.

• Absolute contraindications to warfarin therapy
  • Bleeding diathesis
  • Thrombocytopaenia
  • Poorly-controlled hypertension (blood pressure consistently ≥160/90 mm Hg)
  • Non-compliance with medication or International Normalized Ratio (INR) monitoring
  • Previous intracranial bleed or retinal haemorrhage
  • Recent gastrointestinal/genitourinary bleeding
  • First trimester and last month of pregnancy
• Relative contraindications to warfarin therapy
  • Significant alcohol use (>60 mL/day or >5 standard drinks/day) or liver disease
  • Conventional non-steroidal anti-inflammatory drug (NSAID) use (without cytoprotection)
  • Participation in activities predisposing to trauma
  • Unexplained anaemia
  • Dementia
  • Multiple comorbidity
  • Unexplained recurrent syncope
• People with atrial fibrillation/atrial flutter (AF/AFL) who should not receive electrical cardioversion include those with
  • Serum potassium outside the normal range
  • A contraindication to, or intolerance of, conscious sedation or anaesthesia (or anticoagulation, if this is to be given)
  • Digoxin toxicity
  • Advanced conduction system disease
  • Suboptimal anticoagulation
  • Intermittent AF, with periods of sinus rhythm over the immediate precardioversion period
  • A history of clear early relapse, despite optimal pharmacological maintenance therapy
• Beta-blockers are contraindicated in people with asthma
• Beta-blockers, calcium channel blockers (diltiazem, verapamil), and digoxin are contraindicated in people with Wolff-Parkinson-White (WPW) syndrome and especially in those with pre-excited atrial fibrillation (AF).
• The combination of a beta-blocker and verapamil has resulted in severe bradycardia and requires careful monitoring. Intravenous administration of one, in the presence of the other, is contraindicated. If overt heart failure is present, verapamil and beta-blockers are relatively contraindicated.
• Some antiarrhythmic agents are absolutely or relatively contraindicated in certain subgroups of people (see Table 8.3 in the original guideline document).

While the guidelines represent a statement of best practice based on the latest available evidence (at the time of publishing), they are not intended to replace the health practitioner's judgment in individual cases.

Getting Better
Living with Illness

Effectiveness
Patient-centeredness

• New Zealand Guidelines Group (NZGG). The management of people with atrial fibrillation and flutter. Wellington (NZ): New Zealand Guidelines Group (NZGG); 2005 May. 177 p. [422 references]

The guideline is an adaptation of the 2001 ACC/AHA/ESC Guidelines for the Management of People with Atrial Fibrillation, which was developed jointly by the American College of Cardiology (ACC), the American Heart Association (AHA), and the European Society of Cardiology (ESC).

2005 May

New Zealand Guidelines Group - Private Nonprofit Organization

New Zealand Guidelines Group

Guideline Development Team

Team Members: Hugh McAlister (Chair) MB, ChB, FRACP, FCSANZ, Cardiologist, Waikato Hospital, Hamilton, Nominated by the Cardiac Society of Australia and New Zealand; P Alan Barber, PhD, MB, ChB, FRACP, Senior Lecturer, Department of Medicine, University of Auckland, Director, Auckland Hospital Stroke Service, Auckland, Nominated by the Stroke Foundation of New Zealand Inc; Malcolm Clark, MB, ChB, BSc, FRACP, General Physician, Nelson Hospital, Nominated by the RNZCGP; Mavis Fenelon, Specialist Teacher, Consumer Representative, Nominated by the Auckland Heart Group; John Fink, MB, ChB, FRACP, Consultant Neurologist, Department of Neurology, Canterbury District Health Board (DHB), Senior Lecturer in Medicine, Christchurch School of Medicine and Health Sciences, Nominated by the Neurological Association of New Zealand; Matire Harwood, MB, ChB, Ngäpuhi, Research Fellow, MRINZ, General Practitioner, Whai Oranga o te iwi, Nominated by the Mäori Cardiovascular Advisory Group; David Heaven, MB, ChB, FRACP, Consultant Cardiologist, Middlemore Hospital, Nominated by the Cardiac Society of Australia and New Zealand; Margaret Hood, MB, ChB, FRACP, Electrophysiologist/Cardiologist, Auckland Hospital, Nominated by the Cardiac Society of Australia and New Zealand; Lisa Hughes, MB, ChB, FRNZCGP, General Practitioner, Nominated by the RNZCGP; Stephen May, MB, BS MRCP, MRCPath., Consultant Haematologist, Pathology Associates, (Tauranga Hospital Laboratory, Medlab Bay of Plenty, Pathlab Waikato, Rotorua Diagnostic Laboratory) Visiting Haematologist Waikato Hospital, Nominated by Pathology Associates; Lee Pearce, RCompN, ADCCN, BHSc, Dip Bus, Pacific Health, Planning & Funding Directorate, Capital & Coast DHB, Nominated by the Pacific Cardiovascular Group; Tim Wilkinson, MB, ChB, M Clin Ed, FRACP, Consultant Geriatrician, Older Persons' Health, Canterbury DHB, Associate Professor in Medicine, Christchurch School of Medicine and Health Sciences, Nominated by the Stroke Foundation of New Zealand Inc; Andy Williams, MBBS (London), FRNZCGP, General Practitioner, Feilding, Nominated by the RNZCGP; Gabrielle Collison, Clinical Advisor, Clinical Services Directorate, Ministry of Health, Ex-officio Ministry of Health; Sandra Moore, Senior Analyst, Clinical Services Directorate, Ministry of Health, Ex-officio Ministry of Health

NZGG Team: Anne Lethaby (Senior Project Manager) MA (Hons), Dip Soc Sci (App Stats) Senior Researcher, NZGG; Rob Cook, MBBS, FRNZCGP, Project Manager and Medical Adviser, NZGG, General Practitioner, Nominated by the RNZCGP; Naomi Brewer, MMedSci, BSc (Hons) Research Officer, NZGG, Until September 2004; Carole Webb (Assistant Project Manager) BSc (Hons) Assistant Researcher, NZGG, Until June 2004

David Heaven has received financial support towards conference travel from Roche.

Hugh McAlister is a member of the New Zealand AstraZeneca specialist advisory board.

Ministry of Health, New Zealand - National Government Agency [Non-U.S.]
National Heart Foundation of New Zealand - Disease Specific Society
Stroke Foundation of New Zealand, Inc. - Medical Specialty Society

This is the current release of the guideline.

This NGC summary was completed by ECRI on July 25, 2005. The information was verified by the guideline developer on August 19, 2005. This summary was updated by ECRI on March 6, 2007 following the U.S. Food and Drug Administration (FDA) advisory on Coumadin (warfarin sodium). This summary was updated by ECRI Institute on September 7, 2007 following the revised U.S. Food and Drug Administration (FDA) advisory on Coumadin (warfarin).

These guidelines are copyrighted by the New Zealand Guidelines Group. They may be downloaded and printed for personal use or for producing local protocols in New Zealand. Re-publication or adaptation of these guidelines in any form requires specific permission from the Executive Director of the New Zealand Guidelines Group.