June 2007: Tackling the QOF2 indicators for AF
Symposium: Cardiovascular medicine
Symposium: Cardiovascular medicine
How can AF registers be populated?
There are a number of ways that patients with AF can be added to the register. These vary in the effort required and the speed of results.
First, patients can be added to the register as they present for review or with a new diagnosis of AF.
The NICE guidance1 recommends manual pulse palpation to assess for an irregular pulse in patients who present with:
• Syncope or dizziness
• Chest discomfort
• Stroke or TIA.
An ECG should be performed in all patients with an irregular pulse, whether they are symptomatic or not, in whom AF is suspected.
Suspected paroxysmal AF should be investigated with ambulatory monitoring. This may require referral to a specialist, depending on the local availability of such investigations.
Second, some practices may have existing computerised disease registers, which may have coding for AF.
Third, since the prevention of stroke is the driving force behind the QOF2 indicators for AF, it is important to identify those most at risk. This may be achieved by targeted screening, using existing disease registers or by reviewing case records (for example for patients aged over 65 years) to identify those with risk factors.
Risk factors include:
• Valve disease
• Heart failure
• History of myocardial infarction
An additional strategy could be to identify the prescription of drugs that may be used by those with AF, such as warfarin, digoxin and ß-blockers.
Once patients with risk factors or targeted prescriptions are identified, case records can be flagged to indicate the need to check for AF specifically when the patient is next seen. A more proactive approach would be to invite those at high risk for review and possible ECG.
A fourth option is opportunistic screening, taking the opportunity to check for an irregular pulse in every patient, particularly those over 65 years.
The Health Technology Assessment study2 concluded that opportunistic screening was a reasonable and cost-effective strategy compared with systematic screening, and was an improvement on routine practice.
Should patients who have been successfully cardioverted remain on the AF register?
Yes, patients should remain on the AF register following cardioversion. This should be for at least a year in some cases, but for many patients this should be for life. Following DC cardioversion there is a high recurrence rate of AF, even in cases with an absence of structural heart disease, with more than half of patients being back in AF at one year.
Stroke risk should be considered. Patients with mitral valve disease or heart failure remain at high risk of both recurrent AF and subsequent stroke. These patients should continue on warfarin therapy and be included in the AF register. However, young patients with structurally normal hearts and reversible causes will be at low risk of recurrence or stroke. These patients could be safely removed from the AF register after one year.
NICE recommends that a patient should only be discharged from secondary care after six months if sinus rhythm is maintained.
Should patients who have been successfully ablated remain on the AF register?
Ablation has the potential for long-term cure in some patients. Patients with paroxysmal AF, without structural heart disease, have a primary electrical problem that can be cured by removing the triggers (by pulmonary vein isolation). These patients may eventually be removed from the AF register.
Patients with persistent AF, particularly if it has been of long duration, such as a year, or those with structural heart disease, have a higher risk of recurrence of AF and should be retained on the register.
One factor to consider is that some patients have recurrent AF in the months immediately after ablation, which subsequently settles with the long-term benefit from the ablation.
However, symptomatic benefit may not necessarily mean absence of AF, which can be asymptomatic. In addition, some patients with a technically successful ablation will have subsequent recurrence of AF and require repeat procedures. Finally, new atrial arrhythmia, for example left atrial flutter, may result as a complication of the ablation procedure.
Ablation for AF is a potentially complicated and rapidly changing area, and the electrophysiologist involved in the care of the patient should be able to advise about risk of AF recurrence.
Should all practice ECGs for suspected AF be reviewed by a specialist?
It is not necessary for a specialist to review all ECGs, although when a referral is made the specialist should be sent a copy of the diagnostic ECG, if possible.
The ECG is important because there are other causes of an irregular pulse apart from AF, such as atrial or ventricular premature beats. It is important to establish the correct diagnosis, as a major consideration in AF is the decision as to whether to start warfarin, which may be life-long therapy and carries a small but significant risk of bleeding.
For screening purposes, most modern ECG machines will give computer-generated reports, which are fairly accurate; in particular, if the report states that it is sinus rhythm it is unlikely that it has missed AF.
However, if there are concerns about the quality of the recording, with obvious noise or artefact, the ECG should be repeated. If the rhythm appears irregular, but there appear to be P waves preceding some QRS complexes, it is advisable to get an informed opinion before making the diagnosis of AF.
What would be a reasonable review interval for patients on the AF register?
The interval will depend on the patient; whether they have paroxysmal, persistent or permanent AF; whether they are being treated for rhythm or rate control; and how successful that treatment is.
Once a patient is stabilised and free from troublesome symptoms they need only infrequent review, if at all. Clearly, patients on warfarin require regular anticoagulation checks.
How often should thromboembolic risk be reassessed?
Thrombotic risk is unlikely to change suddenly, unless the patient suffers an event, such as a myocardial infarction.
Age is a factor, however, and the NICE guidelines indicate that those over 65 years are at higher risk, and those over 75 years have a further increase in risk.
In addition, NICE states that risk stratification should be reconsidered whenever individual risk factors are reviewed.The authors Authors
Professor Andrew C Rankin
Professor of Medical Cardiology, British Heart Foundation, Glasgow Cardiovascular Research Centre and Glasgow Royal Infirmary
Dr Peter Savill
BSc MB BS PGDipCard
GPSI Cardiology, Southampton