AF Prevalence Is Around 1.6%, Although in the Over 75S It Is Greater Than 10%

Atrial Fibrillation2016.

AF prevalence is around 1.6%, although in the over 75s it is greater than 10%.

AF increases stroke risk 5 fold compared to people without AF.

NICE CG 180 June 2014 advises several changes, including:

-Aspirin is no longer recommended. Anticoagulation needs to be used to reduce stroke risk.

-Rate control should be offered for the majority (1st line).

-CHA2DS2Vasc score (rather than CHADS2) to assess stroke risk.

-HASBLED to assess bleeding risk for all patients.

-Stratify stroke risk for paroxysmal AF and Atrial flutter in the same way as for permanent AF.

-Increased use of left atrial appendage ablation (see later) for those who don’t respond to conventional therapies.

Classification of AF

Paroxysmal = spontaneous resolution within 7 days.
Persistent = > 7 days & indefinite unless cardioverted.
Permanent = > 7 days and sinus rhythm unachievable.

Screening

-No evidence of benefit for population screening in asymptomatic individuals.

-Opportunistic case finding for symptomatic individuals. Check pulse if breathless, palpitations, syncope/dizziness, chest discomfort, stroke/TIA.

ADMISSION is indicated:

-In the presence of compromise, severe or life threatening.

-If new onset AF within 48 hours, to consider immediate cardioversion.

OTHERWISE, manage as per FOLLOWING FLOW CHART:

1/.

CHA2DS2Vasc Score

Stratifies Stroke risk.

Score 2 or more (men and women): offer anticoagulants
Score 1 in men only: consider anticoagulants
Score 1 in women only: no antithrombotics
Score 0 (men and women): no antithrombotics

Risk Factor / CHA2DS2Vasc: maximum=9
Congestive cardiac failure / 1
Hypertension / 1
Age / 1 (if 65-74)
2 (if 75 and over)
Diabetes / 1
Stroke/TIA (history of) / 2
Sex (female) / 1
Vascular disease (MI, PAD, aortic plaques) / 1

HASBLED score

Stratifies bleeding risk.

Score 3 and over identifies high risk of bleeding.

HASBLED criteria(3 or more=high bleeding risk) / Points: maximum =9
Hypertension- uncontrolled (SBP>160) / 1
Abnormal renal function (on dialysis/transplant/cr>200) &/or
Abnormal liver function (chronic hepatic disease eg cirrhosis, or abnormal LFTs eg. Brb >2x upper limit of normal, AST/ALT/ALP>3x upper limit normal) / 1 point for any renal abnormalities
1 point for any liver abnormalities
Stroke / 1
Bleeding (PMH of bleeding tendency/anaemia) / 1
Labile INRs (unstable INRs or INRs frequently not in therapeutic range) / 1
Score 0 if never had warfarin
Elderley (age >65) / 1
Drugs (eg. On aspirin/NSAIDs) or alcohol abuse (1 point each) / 1 or 2

3/.

Anticoagulation

When aspirin is compared with anticoagulants, there is clear benefit from anticoagulation in terms of:

All cause mortality
Ischaemic stroke

There is also a lack of evidence for other antiplatelets eg. Clopidogrel.

Benefits of anticoagulation:

Compared with placebo, NICE found anticoagulants (basically this means warfarin):

Reduced all cause mortality:22 fewer per 1000 treated
Reduced ischaemic stroke: 37 fewer/1000 treated

(NICE give no time frames, probably 1y)

Warfarin

Target for treatment:

INR 2.5 (2-3)

Warfarin in older people:

NICE suggests that :

For most, the benefit of anticoagulation outweighs the risks.
We should NOT withhold warfarin solely because the person is at risk of having a fall.

Warfarin: assessing time in therapeutic range:

Aim for a time in therapeutic range (TTR) of more than 65%

(TTR should be calculated over at least 6 months, excluding the initial 6 weeks)

Poor control is shown by (in last 6months):

TTR of 65% or less
1 INR higher than 8
2 INRs higher than 5
2 INRs less than 1.5

Remember to ask regarding alcohol intake, as well as cognitive function, compliance, other medication.

Note: INR >8 – admit to consider Vit K administration.

Raised INR ( 3 to <8) – patient is likely to be advised by anticoag clinic re dose omission

and plan.

INR (any) + significant bleeding = admit.

Warfarin MAY be used with antiplatelets if the patient has also had an MI, for 2o prevention of cardiovascular disease . These are secondary care decisions and may be for a limited period of time eg. 1 year post MI. Note that newer antiplatelets eg. Prasugrel, ticagrelor and NOACs should not be used in combination due to lack ofevidence.

Remember, if the plan is not clear in the notes, use Advice and Guidance Choose and Book referral to cardiology to confirm the plan.

4/.

Initiation of warfarin:

Instructions (as below) are on the referral form. Link to form with guidance are on Atrial Fibrillation Template on Mothership.

Ensure bloods are checked as per flow chart, prescribewarfarin 2mg od for 7days. Patient to attend blood testing on D7 or 8 at CRH (or RHI), where INR will be checked and counselling re warfarin will be offered in pharmacy.

For housebound patients, fax a referral to the anticoagulation clinic and they will make arrange to visit the patient at home.

NOACs

NICE advises offer NOACs or warfarin as thromboprophylaxis, provided use is within the NICE guideline for each NOAC (see later). Basically, this means a NOAC can be offered in place of warfarin, in non valvular AFif any of the following risk factors are present:

Stroke/TIA
Diabetes
Heart failure
Hypertension
Over 75 years of age

HOWEVER, SIGN remind us (SIGN 129,2012)

The relative lack of experience of use of NOACs.
Lack of an antidote
Higher rates of GI bleeding (but fewer intracranial bleeds), especially with higher doses and in the elderly (total bleeding risk the same).

No head to head trials between NOACs, but all 3 NOACs seem to be broadly similar with regard to bleeding risk and stroke prevention.

Note: poor compliers on warfarin may also be poor compliers on NOACs. NOACs also have a short half life, so anticoagulation may be erratic in result – but you won’t know, because it isn’t being measured.

Beware renal impairment and abnormal liver function when considering NOACs. See prescribing guidance. Care ++ therefore, if suspected alcohol abuse .

Dabigatran

Inhibits thrombin

Ref: NICE 2012 TA249

Dose 150mg bd or,

110mg bd if > 80 years old (or if 75-80 with high bleeding risk/low

thromboembolic risk)

Beware renal impairment. Use lower dose of 110mg bd if eGFR 30-50.

Check eGFR before start and annually if >75, weight <50kgor eGFR 30-50

Rivaroxaban

Direct factor Xa inhibitor

(also licensed for treatment and prevention of recurrence of VTE)

Ref: NICE 2012 TA256

5/.

Dose 20mg od with evening meal.

Note dose adjustment with renal impairment eGFR <50, see BNF.

Apixaban

Direct factor Xa inhibitor

Ref: NICE 2013 TA275

Dose 5mg bd.

Reduced dose eGFR<30 or if at least 2 of: >80y, <60kg or Creat >133 (2.5mg bd)

Beware hepatic impairment – do not use if transaminases >2x upper limit of normal.

Common Side Effects of all 3:

Nausea, GI upset, bleeding and anaemia.

Initiation & monitoring

Document counselling: Risks, benefits, importance of compliance, review schedule and when to seek medical help etc

Provide a PILeaflet -

Ensure that FBC, Clotting, Renal function and LFTs are checked pre-treatment, at six weeks post initiation and annually, thereafter. (TSH only needs to be checked pre-treatment).

Also at annual review check compliance and repeat HASBLED scoring (if > or = 3 consider requires GP review re ? continue anticoagulation ? any modifiable risk factors)

Switching from Warfarin to a NOAC

GP-Update suggests as below – taken from SPC Jan 2013 – as well as considering advice from a local expert.

Dabigatran / Rivaroxaban / Apixaban
Stop warfarin.
Start dabigatran as soon as INR is <2.0. / Stop warfarin.
Start rivaroxaban when INR is <3.0.
Note: when on rivaroxaban the INR values will be falsely elevated. / Stop warfarin.
Start apixaban when INR is <2.0.

Note: all NOACs are licensed for prevention of VTE after elective hip/knee replacement.

Left Atrial Appendage Occlusion.

In those whom anticoagulation is not tolerated or contraindicated – offer left atrial appendage occlusion if:

-Persistent AF

-Paroxysmal AF

The left atrial appendage is the embryological remnant of the left atrium and is a little blind ending passage/sac off the left atrium. There is a risk of stasis and thrombus formation and it is thought to be a major source of thrombus in AF. It can be done in the catheter lab.

Rate Control

For the vast majority. See Flow chart on page 2.

Aim for pulse 80-90.

Beta Blocker (any except sotalol) or,
Rate Limiting Calcium Channel Blocker (usually diltiazem)..The latter are unlicensed, but recommended by NICE.
Only consider digoxin if sedentary patient with non-paroxysmal AF

Do NOT use amiodarone.

6/.

If monotherapy ineffective, try dual therapy with any two of 1., 2., or 3.

If dual therapy ineffective, refer – rhythm control or ablation.

Rhythm control

For a minority. See Flow chart on page 2.

Electrical cardioversion

is 1st choice (can add amiodarone from 4w previous to 12m post cardioversion to help maintain sinus rhythtm once restored)

Can be done in standard way needing INRs for 4 weeks in therapeutic range or, with transoesophageal echo as guidance without prolonged anticoagulation (can check that there is no thrombus in the heart)

Drug treatment.

This should be a cardiologist’s decision to maintain sinus rhythm after cardioversion.

1st line – standard beta blocker (not sotalol), then

Dronedarone(a secondary care drug)– after successful cardioversion and 1st line

treatment has failed andwho have at least 1 of the following cardiovascular risk

factors:

Hypertension on rx with drugs of at least 2 different classes.
Diabetes mellitus
Previous TIA, stroke or systemic embolism
Left atrial diameter of 50mm or greater or,
Age 70 years or older and,

-Who do not have left ventricular systolic dysfunction and,

-Who do not have a history of, or current, heart failure.

Consider amiodarone for those with LVimpairment or heart failure.

Do not offer class 1c antiarrhythmics – flecainide or propafenone - to those with ischaemic or structural heart disease

Pill in the Pocket

For patients with paroxysmal AF with infrequent episodes and few symptoms or known trigger eg. caffeine or alcohol – can consider no treatment or ‘pill in the pocket’eg. flecainide in those who:

Have no LV dysfunction,valvular or ischaemic heart disease

Have infrequent, symptomatic episodes
Have systolic BP>100mm hg and resting pulse >70
Are able to understand how and when to use the medication.

Surgical techniques

If drug treatment fails to control symptoms of AF or high ventricular rate consider:

Left atrial catheter ablation (paroxysmal AF)

Left atrial surgical (or catheter) ablation (persistent AF).

Discuss risks and benefits with each person.

Pace and AV node ablation (permanent AF and symptoms or high ventricular rate and LV dysfunction).

7/.

Paroxysmal AF

Stroke prevention – assess for anticoagulation as for all AF using CHA2DS2Vasc and HASBLED, then REFER to consider:

Long term rhythm control or ‘pill in the pocket’ (as in 3. Above).

Offer a Personalised Package of Care

Go to AF personalised package of care auto-consult on S1, link on Atrial Fibrillation template. As per NICE:

Ensure that the package of care is documented and delivered, and that it covers:

stroke awareness and measures to prevent stroke
rate control
assessment of symptoms for rhythm control
who to contact for advice if needed
psychological support if needed
uptodate and comprehensive education and information on:

-cause, effects and possible complications of AF

-management of rate and rhythm control

-anticoagulation

-practical advice on anticoagulation in line with recommendation 1.3.1 in ‘Venous thromboembolic diseases (NICE CG 144)

-support networks (eeg. Cardiovascular charities)

Issue appropriatePILs from Atrial Fibrillation Template on mothership.

QOF Rules

- AF001: register

- AF003: in those patients with AF in whom there is a CHADS2 score of 1, the percentage of patients who are currently treated with an antiplatelet agent or anticoagulation.

- AF004: in those patients in whom there is a record of CHADS2 score >1, the percentage of patients who are currently treated with anticoagulation.

8/.

References:

NICE CG180 (update June 2014)

Greater Huddersfield Commissioning Group (GHCCG) QOF QP Pathway.