New arrhythmia guidelines released

To counter the increased prevalence of heart arrhythmia — a major cause of stroke in Australia — new guidelines for diagnosing and managing atrial fibrillation (AF) have been released by the National Heart Foundation of Australia (NHF) and the Cardiac Society of Australia and New Zealand (CSANZ).

AF is an arrhythmia (irregular heartbeat) diagnosed on electrocardiogram; an episode lasting at least 30 seconds is considered diagnostic.

The new guidelines are designed to assist Australian health professionals improve patient outcomes including improvement in symptoms, reduction in hospital admissions, prevention of stroke, appropriate use of the latest evidence-based care, timely diagnosis and, of course, survival. They stress the importance of patient-centred care and shared informed decision-making, especially regarding the use of anticoagulant (blood thinning) medications to prevent stroke.

While international guidelines on AF exist, the authors of the new recommendations state that “individual recommendations may differ, and no guidelines have previously been developed specific to the Australian population”. The heart failure guidelines are intended to replace the 2011 update of the National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (NHFA/CSANZ) Guidelines for the prevention, detection and management of chronic heart failure in Australia.

Australian AF profile

It is estimated that almost 3% of Australian adults are currently living with atrial fibrillation,^{1, 2} equating to more than half a million Australians. However, true prevalence is underestimated due to the frequency of subclinical AF.³ 

AF rates also increase significantly with age,^{1, 2} and are more prevalent in Aboriginal and Torres Strait Islander peoples due to higher rates of cardiovascular disease.⁴

In Australia, the prevalence of AF in people aged 55 years or more is expected to double over the next 20 years as a result of an ageing population and improved survival from contributory diseases.⁵ In the past decade (from 2007 to 2016), deaths from atrial fibrillation have increased by 82%, with 15,960 Australians having lost their lives due to AF in the last decade.⁶ These figures likely underestimate the true number of deaths associated with AF as they do not account for death caused by AF-related conditions such as stroke and heart failure. AF is a major cause of stroke in Australia.

Changes in management

Changes in management as a result of the guidelines include:

• Opportunistic screening in the clinic or community is recommended for patients over 65 years of age.
• The importance of deciding between a rate and rhythm control strategy at the time of diagnosis and periodically thereafter is emphasised; beta-blockers or non-dihydropyridine calcium channel antagonists remain the first line choice for acute and chronic rate control; cardioversion remains the first line of choice for acute rhythm control when clinically indicated; flecainide is preferable to amiodarone for acute and chronic rhythm control; failure of rate or rhythm control should prompt consideration of percutaneous or surgical ablation.
• The sexless CHA2DS2-VA score is recommended to assess stroke risk, which standardises thresholds across men and women; anticoagulation is not recommended for a score of 0, and is recommended for a score of ≥2; if anticoagulation is indicated, non-vitamin K oral anticoagulants are recommended in preference to warfarin.
• An integrated care approach should be adopted, delivered by multidisciplinary teams, including patient education and the use of e-health tools and resources where available; regular monitoring and feedback of risk factor control, treatment adherence and persistence should occur.
   

The full clinical guidelines for atrial fibrillation can be found here.
The full clinical guidelines for heart failure can be found here.

Executive summaries of both sets of new guidelines have been published by the Medical Journal of Australia.

References

1. Ball, J., M.J. Carrington, J.J.V. McMurray, et al., Atrial fibrillation: profile and burden of an evolving epidemic in the 21st century. International Journal of Cardiology, 2013. 167(5): p. 1807-1824.

2. Briffa, T., J. Hung, M. Knuiman, et al., Trends in incidence and prevalence of hospitalization for atrial fibrillation and associated mortality in Western Australia, 1995–2010. International Journal of Cardiology, 2016. 208: p. 19-25.

3. Lowres, N., L. Neubeck, J. Redfern, et al., Screening to identify unknown atrial fibrillation. A systematic review. Thrombosis and Haemostasis, 2013. 110(2): p. 213-222.

4. Katzenellenbogen, J.M., T.H.K. Teng, D. Lopez, et al., Initial hospitalisation for atrial fibrillation in Aboriginal and non-Aboriginal populations in Western Australia. Heart, 2015. 101(9): p. 712-9.

5. Ball, J., D.R. Thompson, C.F. Ski, et al., Estimating the current and future prevalence of atrial fibrillation in the Australian adult population. MJA, 2015. 202(1): p. 32-36.

6. Australian Bureau of Statistics, Causes of Death 2016, ABS cat. no. 3303.0, September. 2017.

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