In the first article of our new series on QOF2 Dr Alan Begg gives practical evidence-based advice on meeting the indicators for atrial fibrillation

Atrial fibrillation (AF), the most common cardiac dysrhythmia, is associated with significant morbidity and mortality. It is therefore appropriate that it should be included as a clinical domain in the update of the quality and outcomes framework (QOF2) which comes into effect in April 2006 (Table 1). Compared with patients with sinus rhythm, patients with AF have on average a five-fold increased risk of a stroke.

The main cause of stroke in these patients is an atrial thrombosis giving rise to a cerebral embolus.1

Table 1: The clinical indicators for atrial fibrillation

Disease/ indicator no Clinical indicator Points Payment stages
Min (%) Max (%)
AF 1 The practice can produce a register of patients with atrial fibrillation 5    
AF 2 % of patients with atrial fibrillation diagnosed after 1 April 2006 with ECG or specialist confirmed diagnosis 10 40 90
AF 3 % patients with atrial fibrillation who are currently treated with anti-coagulation drug therapy or an anti-platelet therapy 15 40 90

Setting up a register (AF1)

Practices should adopt the same systematic approach to developing this register as they did with QOF1. The register should include patients with permanent and paroxysmal AF.

Patients need to be identified by:

  • searching for the range of Read codes currently being used (Box 1)
  • determining the reason for patients receiving anticoagulation monitoring (currently this may be an enhanced service)
  • a computer search of rhythm control (BNF 2.3.2), oral anticoagulants (BNF 2.8.2), and cardiac glycoside drugs (BNF 2.1.1)
  • looking at those patients who have had associated procedures such as a cardioversion.

Searching through existing disease registers for coronary heart disease (CHD) and stroke may also help identify some patients although the list of patients on rate-reducing drugs, such as beta blockers (BNF 2.4), and rate-limiting calcium channel blockers, such as verapamil and diltiazem, may not be specific enough to identify many patients without examining a large number of patient records.

A system also needs to be put in place to ensure that all newly hospital diagnosed patients are added to the register on an ongoing basis.

Box 1: Atrial fibrillation Read codes
Atrial fibrillation G5730
Atrial fibrillation and flutter G573
Paroxysmal atrial fibrillation G5732
Atrial flutter G5731
Non-rheumatic fibrillation G5733
Atrial fibrillation and flutter NOS G573z

Confirming the diagnosis (AF2)

Only patients diagnosed after 1 April 2006 require the diagnosis to be confirmed by an ECG or specialist referral (Box 2). It seems impractical that all patients suspected of having AF should be referred to hospital for initial diagnosis, but this will depend on the availability within the practice or local community of ECG facilities and the expertise to interpret them appropriately.

The gold standard of ECG interpretation and diagnosis of AF is seen as analysis by a cardiologist. In a Tayside study in which GPs reviewed ECGs from patients with suspected heart failure that had previously been reported by a cardiologist, GPs correctly categorised 77% (95% confidence interval [CI] 75–78%) of abnormal ECGs and 85% of normal ECGs (95% CI 83–87%).

Ninety three per cent (95% CI 91–94%) of major ECG abnormalities were correctly identified as abnormal.2

Box 2: Atrial fibrillation codes
Cardiological referral
  Left ventricular hypertrophy
  No left ventricular hypertrophy
  Not done
External cardioversion
Direct current cardioversion

Computer-assisted ECG interpretation

GPs may feel that they lack the confidence and expertise to interpret ECGs correctly. Standards have been set for ECG interpretation programs3 but machines that are electrically safe can be marketed in Europe regardless of their interpretation program.4 However, even with good programs, AF will only be diagnosed correctly in 80% of cases.4

The Spacelabs Eclipse 850 in use in our practice has a 95% sensitivity and a 98% specificity for AF with a 92% positive predictive value. This compares with the results from a UK randomised controlled trial (carried out as part of the health technology assessment programme) of 87.3% and 99.1%, respectively (predictive value of 89.5%) against a gold standard of cardiologist reporting.5

In a Danish study GPs were noted to be good at correcting false positive diagnoses made by an interpretive ECG recording6 and the British Heart Foundation has recently advised that "interpretation should not be accepted without consideration of the clinical context and a visual inspection of the ECG, preferably by an expert".4

Clinical evaluation and management

Once a diagnosis of AF has been confirmed a full evaluation and appropriate further investigation is required to guide effective therapy (Table 2 and Table 3).7 For this to be carried out comprehensively, referral to a cardiologist may become imperative, especially if electrical cardioversion needs to be considered.

Table 2: Causes of atrial fibrillation and associated conditions
  • Acute
Alcohol intake
Pulmonary embolism
  • Without cardiovascular disease
Especially in younger people
  • With cardiovascular disease
Valvular heart disease
Coronary heart disease
Hypertension (especially if left ventricular hypertrophy)
  • Neurogenic
Through heightened vagal or adrenergic tone

Table 3: Evaluation of patients with atrial fibrillation
  • History and physical examination
Presence and nature of associated symptoms
Clinical type (first episode, paroxysmal or persistent)
Onset of first attack
Frequency, duration, precipitating factors and modes of termination
Response to administered pharmacological agents
  • ECG with full evaluation
  • Chest X-ray
  • Echocardiogram
  • Thyroid function

Rate versus rhythm control

The presence of AF, especially in elderly patients, increases the risk of stroke and death. A recent Cochrane Review concluded that in the majority of cases there is no evidence that pharmacological cardioversion to sinus rhythm is superior to rate control.8

The former approach was in fact associated with more adverse effects and increased hospitalisation without reducing the risk of stroke. A rate control approach should be considered for all those with permanent AF although this may not be necessary in the elderly who are less active and have a slow ventricular rate.

Rate control should be achieved with the use of beta blockers or rate-limiting calcium-channel blockers, such as verapamil or diltiazem, in combination with digoxin if necessary. Digoxin on its own only controls heart rate at rest and is less effective during exercise or if there is high sympathetic drive, such as in heart failure.

Antithrombotic therapy (AF3)

A recent meta-analysis involving more than 14,000 patients revealed that thromboprophylaxis with warfarin in AF significantly reduced the risk of ischaemic stroke or systemic embolism compared with placebo.9 The risk reduction of stroke did not vary between primary and secondary prevention but the absolute risk reduction for all stroke was greater for secondary stroke prevention.

There were fewer benefits of using aspirin when compared with warfarin and the benefits of aspirin may, in fact, only be reflecting its effect on stroke prevention in vascular disease rather than in AF.10 This mirrors the conclusions from other systematic reviews which show the benefits of warfarin balanced against the risk of haemorrhage in high-risk patients including those with non-rheumatic AF who have had a stroke.11,12

Practices will be required to report the percentage of patients with AF whose records show that they have been prescribed anti-thrombotic drug therapy in the previous 6 months.

Risk factors for systemic thromboembolism

The current SIGN guideline on antithrombotic therapy13 suggests identifying the following risk factors for thromboembolism in patients with AF as a means of risk assessment:

  • previous ischaemic stroke or transient ischaemic attack
  • age over 65 years
  • hypertension
  • diabetes
  • cardiac failure
  • echocardiogram showing left ventricular dysfunction or mitral valve calcification.

Warfarin is recommended in all of the high-risk groups, but in patients aged less than 65 years with non-valvular AF and with none of these risk factors, warfarin is not indicated and aspirin should only be given if there are other indications. Aspirin should be considered in those where warfarin is declined or contraindicated because of an increased risk of bleeding, bearing in mind that it is less effective.

GPs can commence patients on warfarin for long-term prophylaxis with a less intensive starting regimen using locally agreed protocols and aiming for a target international normalised ratio (INR) of 2.5 (Table 4).14,15

Table 4: Less intensive regimen for commencing warfarin15
  • Warfarin 2 mg daily for 2 weeks. Check INR after 1 week
  • Change dose only if INR > 4.0, then omit for 2 days and recommence at 1 mg daily
  • Recheck INR after 2 weeks of anticoagulation and use table to predict maintenance dose
INR (male)
Dose (mg/day)
INR (female)
Dose (mg/day)
Adapted from Br J Clin Pharmacol 1998; 46: 157-16115
  • Check INR weekly for 6-8 weeks
  • Warfarin dose is not changed unless:
    - INR > 4.0, then omit for 2 days and recommence at 1 mg lower or if INR < 1.5 for 2 consecutive weeks, then increase dose by 1 mg
    - If INR is not stable by week 6, 0.5 mg dose adjustments can be made

Exception coding

The risk of haemorrhage with warfarin or aspirin and whether either should be commenced needs to be considered on an individual basis, bearing in mind:

  • associated co-morbidities
  • the risk of falls and exposure to trauma
  • cognitive function
  • ability to adhere to therapy and monitoring regimens.

Exception codes (Box 3) should be recorded in the same way as QOF1.

The contract guidance indicates that anti-thrombotic therapy would not necessarily be indicated if the episode of AF was an isolated event and not likely to recur.

Box 3: AF exception codes
Warfarin not indicated
Warfarin contraindicated
Warfarin adverse reaction
Warfarin declined
Warfarin allergy
Warfarin not tolerated
AR Nicoumalone
AR Phenindione
AR anticoagulants NOS
Aspirin not indicated
Aspirin contraindicated
Aspirin refused
Salicylates - adverse reaction
Aspirin allergy
Aspirin not tolerated
Over counter aspirin therapy
Clopidogrel not indicated
Clopidogrel contraindicated
Clopidogrel declined
Clopidogrel allergy
Clopidogrel adverse effect
Clopidogrel not tolerated



Management of patients with atrial fibrillation can be complex as they often have multiple co-morbidities and inter-related conditions. Practices need to implement a programme of regular structured review with computerised call and recall, using the most appropriate member of staff with the correct training and skill mix.


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  3. Willems JL, Abreu-Lima C, Arnaud P et al. The diagnostic performance of computer programs for the interpretation of electrocardiograms. N Engl J Med 1991; 325: 1767-73.
  4. Computer-Assisted ECG Interpretation British Heart Foundation Factfile.
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  11. Saxena R, Koudstaal P. Anticoagulants versus antiplatelet therapy for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischemic attack. Cochrane Database Syst Rev 2004; 4: CD000187.
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  13. Scottish Intercollegiate Guidelines Network. (SIGN Guideline 36). Antithrombotic Therapy. Edinburgh: SIGN, 1999.
  14. Tait RC, Sefcick A. A warfarin induction regimen for out-patient anticoagulation in patients with atrial fibrillation. Br J Haematol 1998; 101: 450-4.
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Guidelines in Practice, March 2006, Volume 9(3)
© 2006 MGP Ltd
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