Intended for healthcare professionals

Views & Reviews From the Frontline

Bad medicine: atrial fibrillation

BMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f4910 (Published 07 August 2013) Cite this as: BMJ 2013;347:f4910

Re: Bad medicine: atrial fibrillation

We write to congratulate the BMJ on the apt name of this article (BMJ 2013;347:f4910). Indeed, the paper highlights some excellent examples of bad medicine.
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It is only human to rely excessively on personal experience, and unconsciously to apply weight to information that supports ideas with which we already have sympathy. These habits constitute a formidable enemy of sound conclusions; and the development of modern scientific method has been driven by the need to eliminate the impact of such bias. It is of particular importance in medicine where the stakes are not profit or glory, but life, disability, pain, dignity and independence.
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As a patient advocacy organisation, AF Association daily helps patients and physicians to access and understand clinical data, and to recognise and avoid the pitfalls of anecdote and hearsay. We look forward to using this article to demonstrate that physicians are just as human as their patients, and to illustrate the challenges that people might face when ensuring that the care they receive from the medical professional is founded on the best evidence.
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We will first explain to our members that
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1) The number of AF patients within a single GP practice is likely to be 20 to 30 (assuming a practice size of 2000 to 3000 patients/practitioner and a 1% prevalence of AF). Even if our estimates are wildly inaccurate the experience of a single GP, including a ‘canary of epidemiology’, will still be at a vast disadvantage when compared to a large randomised controlled trial.
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2) That anticoagulation therapy is no more impossible to stop than treatment with aspirin.
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3) That it is important not to conflate stroke that is a consequence of atherosclerotic disease with stroke as a consequence of cardiac arrhythmia.
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4) That a significant barrier to effective stroke prevention in AF arises from physicians believing aspirin to be a ‘safe’ alternative to warfarin, despite overwhelming evidence that the bleeding risk is the same for both but the reduction in risk from stroke with aspirin is significantly and substantially worse.
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If an AF patient is offered aspirin for stroke prevention, it will almost certainly be accompanied by all manner of habitual justifications that fail in the spotlight of scientific scrutiny. For example, it is oft suggested that elderly patients are at greater risk of bleeds because they are at greater risk of falls. With reference to the available evidence, we find that a patient would need to fall over 200 times a year before the benefit of the warfarin was outweighed by the risk of the falls.
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In the face of such prescribing behaviour, a discussion of the merits of CHA2DS2-VASc or prevailing rates of stroke becomes strikingly irrelevant.
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If a patient suspects that a preference for aspirin over warfarin is financial in origin, the AF Association can guide the patient and physician to evidence that the cost of avoidable strokes is far greater than any difference between the cost of aspirin and warfarin therapy. When considering the newer alternatives to warfarin, perhaps the UK should establish an expert, independent group to evaluate the cost effectiveness of these drugs so that physicians don’t have to analyse huge amounts of data themselves? If this course were followed, we could name it the National Institute for Health and Care Excellence.
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Finally, it is vital to repeat that AF is a cardiac arrhythmia with potentially fatal ischaemic consequences; it is not an atherosclerotic disease and should not be so treated. The AF Association is engaged in a constant effort to ensure that arrhythmias are treated separately from, and not confused with, atherosclerotic disease. The impact of smoking cessation, antihypercholesterolaemia agents, blood pressure reduction and diet modification have had a profound impact on atherosclerosis and its downstream ischaemic consequences. Yet these factors have had little impact on the arrhythmic causes of apparently similar events: sudden cardiac arrest and cardiogenic embolic stroke. To suggest that a reduction in vascular disease should be conflated with a reduction in AF-mediated stroke demonstrates a clinical misunderstanding of the difference between diseases of the heart’s plumbing and diseases of the heart’s electrics.
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Whatever its motivations, the article provides unwelcome refuge for the hard of understanding and fallacious ammunition for opponents of change and practice improvement. We ask that this letter be published in both the print and online outlets of the BMJ as a small measure to counteract the above consequences.
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Medical Advisory Committee, Trustees and CEO of the AF Association
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Competing interests: No competing interests

12 September 2013
Trudie Lobban MBE
CEO, AF Association
Dr Matt Fay, Dr Adam Fitzpatrick, Dr Andrew Grace, Professor Gregory Lip, Professor Richard Schilling, Dr Andreas Wolff
AF Association
PO Box 6219 Shipston-on-Stour Warwickshire CV37 1NL