Do you know how to best reduce your AF patients' risk of stroke?
NICE AF Guideline: Key Recommendations for Primary Care
Kathryn E Griffin
RCGP Clinical Champion for Kidney Care
GP specialist in Cardiology at York Teaching Hospital FT
The National Clinical Guideline Centre (NCGC) recently published updated NICE guidance on Atrial Fibrillation (CG 180)
Why is this important for Primary Care?
Atrial Fibrillation (AF) is increasing in prevalence in the population and is particularly common in people over the age of 75. It is commonly associated with other long term conditions such as cardiovascular disease, hypertension and CKD and so will be identified in patients having their annual reviews for QOF and over 75 Care Reviews.
People with AF are at high risk of embolic stroke, which can be significantly reduced by the use of anticoagulation and it is important for primary care physicians to assess the risk of stroke and to offer appropriate therapy to reduce the risk of stroke. This should be offered as part of a personalised package of care which again fits well with the over 75 Care Plan Approach and enhanced services reducing unplanned hospital admissions.
Who is at low risk for stroke with AF?
It is important to use a validated risk tool to identify stroke risk. The new guideline recommends that we use the CHA2DS2-VASc stroke risk score to assess risk in people with symptomatic or asymptomatic paroxysmal, persistant or permanent AF or atrial flutter or in those people who have had rhythm management for AF with cardioversion or ablation.
The CHA2DS2-VASc score gives an increased stratification with age, and adds the increased risk associated with cardiovascular disease and female sex.
If people with AF are not talking an anticoagulant then stroke risk should be reassessed on a regular basis. All people seen to be at risk of AF related stroke should be counselled about intervention with anticoagulation and those at true low risk do not require intervention.
How is bleeding risk assessed?
It is important to be able to balance an individuals' risk of bleeding with their risk of stroke before commencing therapy associate with increased bleeding risk, however the objective should be to identify modifiable risk factors such as uncontrolled hypertension, concurrent medications such as NSAID, and home circumstances which may promote trips and falls. There is evidence that for most people the benefits of anticoagulation outweigh the bleeding risks.
What is the best way to reduce the risk of stroke?
The CHA2DS2-VASc score is the best way to identify those people who are at low risk of stroke. The guidelines recommend that we should not offer stroke prevention to people under 65 years with no other risk factors then female sex.
The guidelines recommend that we offer anticoagulation for people with a score of two or more taking bleeding risk into account. We should discuss the options for anticoagulation with the person and base the choice on their clinical features and preferences.
The NOAC drugs Apixaban, Dabigatran and Rivaroxaban are all recommended for use in line with the NICE Technology Appraisal for the individual drugs. For people taking Warfarin the potential risks and benefits of switching should be considered in light of the level of their INR control. It is important for prescribers to understand the differences between these drugs to enable the most appropriate agent to be selected by and for an individual.
What about the use of Warfarin?
When people are taking Warfarin it is important to assess the time in therapeutic range at each visit using a validated method assessment and to review those people with
- Two INR values higher than five or 1 value higher than eight in the past six months
- Two INR values less than 1.2 within the past six months
- TTR less than 65 per cent
Evidence from trials show that Warfarin is as effective as the newer agents when TTR is > 65 per cent and it is important to remember that for an individual being under anti-coagulated puts them at the same risk of stroke as not taking the medication at all.
What about the use of aspirin?
The guideline states that antiplatelet therapy should not be used for stroke prevention in people with AF. This includes combined therapy with Aspirin and Clopidogrel.
What about rate and rhythm control?
Control of heart rate is first line except in
- people with a reversible cause
- people with heart failure due to AF
- acute new onset AF
- atrial flutter
as the sooner this population sees an EP consultant (cardiologist specialising in electrophysiology) the more likely an ablation approach would be effective.
A standard beta-blocker (any other than Sotalol) or a rate limiting calcium channel blocker should be used. Digoxin may be added in as second line or used only for sedentary individuals as first line because it does not block the heart rate response to activity. Rhythm control is considered for those people as stated above and in those who have difficult symptoms despite attempts at rate control.
Which people with AF should be referred to a specialist?
Specialist referral is recommended at any stage when treatment fails to control symptoms. Those people who present acutely unwell with AF should be referred for rapid assessment in the emergency department. Standard beta blockers are used as first line treatment unless there are contra-indications however other agents are generally reserved for specialist use. People with AF and heart failure may benefit from heart failure services. There are specialised treatments available for control of rhythm such as left atrial catheter ablation which is more effective for paroxysmal AF in people with an otherwise normal heart pathway ablation for atrial flutter and a pace and ablate strategy when it is just not possible to control the heart rate.
What information is available for patients and carers?
The NICE guideline will be produced as a patient friendly version but there are also very helpful sources for patients and carers from the Atrial Fibrillation Association and the British Heart Foundation. There are also helpful sources available for professionals from these organisations.
NICE AF guidance
NICE AF pathway