grampian primary care atrial fibrillation guidelines 2010

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Grampian Primary Care Atrial Fibrillation Guidelines 2010

Grampian Primary

Care Atrial Fibrillation

Guidelines 2010

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Contents

A INTRODUCTION …………………………………………………………............................................................ 3

B INVESTIGATIONS USED IN ATRIAL FIBRILLATION …………………………………………………………………. 4

C CLASSIFICATION OF AF ; The 3 P’s …………………………………………………………………………………… 4

D TREATMENT OF ATRIAL FIBRILLATION ………………………………………………………………………………….

1. MANAGING THE HEART RATE + / OR RHYTHM ……………………………………………………….

(a) Rate Control ……………………………………………………………………………………………………..

(b) Rhythm Control …………………………………………………………………………………………………

2. REDUCING THE THROMBOEMBOLIC RISK ……………………………………………………………….

3. ESTIMATING THE BLEEDING RISK …………………………………….........…………………………….

4. IDENTIFYING AND TREATING THE UNDERLYING CAUSE…………………………………………..

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5

6

7

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10

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E SUMMARY AND TABLES ……………………………………………………………………………………………….. . 12

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A. INTRODUCTION

Atrial Fibrillation (AF) represents an epidemic of a disease which causes strokes, with a current prevalence of 1.2% of the total population, rising to 4% in the over 65’s, with 10% or more of the over 80 year old population being affected.

The vast majority of patients with Atrial Fibrillation can be managed within Primary Care.

Atrial Fibrillation can lead to considerable morbidity and mortality and cause:

Breathlessness / Heart Failure

Chest Pains / Angina

Palpitations

Dizziness / Syncope

Impaired cognitive Function (repetitive micro emboli and Alzheimer’s Disease)

Tiredness

Stroke / TIA / Systemic Embolism

.

Treatment is aimed at

1. Managing the: a) heart rate (and / or) b) rhythm

2. Reducing the thrombo-embolic risk

3. Identifying and managing the underlying cause

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B. INVESTIGATIONS USED IN ATRIAL FIBRILLATION

The Heart Charity: Arrhythmia Alliance recommends pulse screening for possible AF. (If pulse is found to be irregular, an ECG should be performed)

The possible aetiological factors for the Atrial Fibrillation should be considered in all

patients.

The following investigations should be performed in Primary Care in all patients with Atrial

Fibrillation:

ECG

Blood tests : FBC TFT’s U+E’s LFT’s (INR if anticoagulation being considered)

ECHOCARDIOGRAM (Direct Access ECHO if patient not being referred to

cardiologist:- try to control the ventricular rate at least before referral as LV

dysfunction may be exaggerated at rapid rates)

If patients are suspected of having Paroxysmal Atrial Fibrillation (PAF) either a Holter

Monitor or Event Recorder (if attacks > 24-48 hours apart) should be performed. A 12 lead

ECG during episode of symptoms would be even better.

C. CLASSIFICATION OF AF : The 3 P’s

TYPE DESCRIPTION TREATMENT

First attack No previous AF None (but should still

have echo performed and

thromboembolic risk assessed)

Self limiting

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RECURRENT AF

Paroxysmal Spontaneous termination Rate or Rhythm

within 1-2 days (seldom control

attacks > 7 days)

Persistent Non-self terminating Rate or Rhythm

Intervention needed to control

stop AF

Permanent AF Dominant rhythm Rate control

Conversion not needed

or not attempted

D. TREATMENT OF ATRIAL FIBRILLATION

After managing any underlying cause (eg. thyrotoxicosis, infection) decisions need to be

made regarding:

1. MANAGING THE HEART RATE + / 0R RHYTHM

Ideally all patients would be restored to sinus rhythm but in practice this is difficult to

maintain and therefore a rate approach is usually recommended with only a minority of

patients requiring cardiology (or GPwSI) referral for consideration of cardio-version for

rhythm control.

QIS (Quality Improvement Scotland) recommend that rate versus rhythm options should be

discussed with all patients and recorded in their medical records.

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a) RATE CONTROL

The following factors would guide one more towards RATE CONTROL:

Age > 65 years

Long duration of AF > 1 year

Contraindication to anti-arryhthmics

Severe structural heart disease

Significant left atrial enlargement

Traditionally the aim of rate control was to reduce the heart rate to 60 – 80 bpm at rest

(and 90 – 115 bpm during moderate exercise), although recent research suggests that

this may not always be necessary, providing that patients remain asymptomatic if their

ventricular rate (on ECG, not pulse) is less than 110 bpm at rest. This approach of LENIENT

rate control only applies to ENTIRELY ASYMPTOMATIC patients.

Should they become symptomatic, re-evaluation of LV Function by ECHO and stricter rate

control should then be achieved.

The following drugs are used to control heart rate

(None may be required if rate well controlled)

β-Blockers (eg. Atenolol, Bisporolol) ↓ resting and exercise HR

Rate- Limiting Calcium Channel Blocker :

(non-hydropyridine) ↓ resting and exercise HR

eg. Diltiazem or Verapamil Must NOT be used along with β-Blocker unless pacemaker

implanted or under specialist advice.

Digoxin weak A-V blocker, NOT first-line

may be used as adjuvant therapy

Others (eg. Amiodarone) Where conventional drugs unsuccessful

Amiodarone is rarely used to control the ventricular

rate and should only be commenced by a SPECIALIST

because of its potential side-effects.

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OTHER TREATMENTS:

Other treatments which might be considered by a specialist include: pacemaker insertion,

hybrid therapy (pacemaker plus drugs), catheter ablation (A-V junction: ablate and pace)

b) RHYTHM CONTROL

The following factors would guide one more towards RHYTHM CONTROL:

Symptomatic patients (despite adequate rate control)

Inability to adequately control rate (with associated symptoms)

Younger patients

Presenting first time with absence of major structural heart disease

Secondary to treated or corrected precipitant

Congestive Heart Failure

Patients being considered for RHYTHM CONTROL require FULL anti-coagulation for 3 to 4

weeks prior to cardio-version (whether electrical or pharmacological) unless the onset AF

duration is less than 48 hours. Anti-coagulation is required for at least 4 weeks after

successful cardio-version to sinus rhythm.

A high proportion of patients who are cardio-verted from AF to sinus rhythm will relapse

back into AF and may require further cardio-version with concomitant use of anti-

arrhythmic drugs if not used previously.

UNSUITABLE FOR CARDIO-VERSION:

Contra-indication to anti-coagulation

Structural Heart Disease (mitral stenosis, large left atrium > 5.5cm)

History of multiple failed attempts at cardio-version +/or relapses (even with

concomitant use of anti-arryhthmics)

Ongoing but reversible cause of AF (eg. Untreated thyrotoxicosis)

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PAROXYSMAL ATRIAL FIBRILLATION:

Anti-arrhythmic drugs for RHYTHM control should be tried prior to consideration of

ablation.

Start off with a beta blocker then if ineffective refer to secondary care for consideration of a

class 1c drug eg Flecainide, possibly Sotalol, Dronedarone or Amiodarone.

Ablation may be performed by catheter (or rarely surgical) ablation procedure and can be

particularly useful in troublesome, drug refractory Paroxysmal (or occasionally persistent)

Atrial Fibrillation.

2. REDUCING THE THROMBOEMBOLIC RISK

Epidemiological studies consistently point to AF being the cause of between 15% and 20% of all thrombo-embolic strokes. There is also strong evidence suggesting that AF is associated with some of the worst

strokes in terms of subsequent morbidity and mortality.

Certain co-morbid factors have been reliably identified as particular high-risk factors for

stroke in patients with Atrial Fibrillation. Stroke risk in AF is not homogenous however, and

depends on an individual patient’s profile of stroke risk co-factors: many patients face an

annual stroke risk of between 4% up to 35%.

Because this risk of stroke / TIA or systemic embolism increases when certain risk factors are

present, it is recommended that all patients have a risk assessment as to whether they

require anti-coagulation.

Patients with valvular heart disease (moderate or severe valvular stenosis or regurgitation)

require warfarin therapy (unless contraindicated) regardless of additional risk factors.

Patients with non-valvular AF should have a CHA2DS2-VASc (or similar) risk assessment

performed (a QIS standard).

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CHA2DS2-VASc scoring is shown below :

RISK FACTOR SCORE

C Congestive Heart Failure or LVF 1

(includes asymptomatic LV systolic dysfunction)

H Hypertension 1

A2 Age > 75 years 2

D Diabetes Mellitus (presence of) 1

S2 Stroke or TIA previously 2

V Vascular Disease 1

A Age 65-74 years 1

Sc Sex category (ie. female gender) 1

( Maximum score = 9 )

The total score is calculated and the following recommended:-

Total Score: 0 : None or aspirin

1 : Aspirin or warfarin

≥2 : Warfarin

An INR range of 2-3 is recommended for non-valvular AF (with an optimal level being 2.2 -

2.3).

Novel anti-coagulant agents which do not require INR monitoring might become available

in the near future but their cost may preclude their use.

BLEEDING RISK : Balancing stroke prevention against the bleeding risk

It is recommended that warfarin should be prescribed if the CHA2DS2-VASc score is ≥ 2

unless the patient has a high risk of bleeding.

Because oral anticoagulants including warfarin, carry the risk of bleeding , various bleeding

risk calculators have been developed to fine-tune the treatment of AF. One of these is the

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HAS-BLED calculator whereby a score of ≥ 3 indicates “high risk” , and some caution and

regular review of the patient is needed following the initiation of antithrombotic therapy

whether with warfarin or aspirin.

HAS-BLED scoring is shown below :

RISK FACTOR SCORE

H Hypertension 1

A Abnormal liver/renal function 1-2

S Stroke 1

B Prior major Bleeding or predisposition 1

L Labile INR 1

E Elderly (>65) 1

D Drugs/alcohol concomitantly 1-2

Where : -

Hypertension : SBP > 160mmHg (despite treatment)

Abnormal Renal Function : chronic dialysis, renal transplant, or serum creatinine ≥ 200

µmol/l

Abnormal Liver Function: chronic hepatic disease (eg. cirrhosis) or significant

biochemical derangement ( bilirubin ≥ 2X upper limit of

normal, in association with AST/ALT/Alk Phos ≥ 3X upper limit

of normal)

Bleeding : previous bleeding history +/or predisposition. (eg. bleeding

diathesis, anaemia

Labile INR : unstable high INR or <60% within therapeutic range

Drugs/alcohol : concomitant use of antiplatelet agents, NSAID’s etc

PAROXYSMAL ATRIAL FIBRILLATION (PAF) probably carries the same thrombo-embolic risk

as persistent AF and so the same risk scoring (eg. CHA2DS2-VASc) is applicable in PAF.

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Performing a DCCV does not reduce future thromboembolic risk even if apparently

successful in restoring long-term SR. Indication for warfarin will still be based on overall

thromboembolic risk. (ie cardioversion does not remove the need for anticoagulation long-

term)

3. IDENTIFYING AND TREATING THE UNDERLYING CAUSE

The causes of the Atrial Fibrillation (eg. Hypertension, Ischaemic Heart Disease, Heart

Failure, Valvular heart disease, thyrotoxicosis, etc) should always be considered and

addressed where appropriate.

E. SUMMARY

AF is a common condition and can largely be managed in primary care. When certain clinical

circumstances prevail (eg. younger patients, haemodynamically challenged, heart failure,

refractory symptoms) secondary referral should be considered for possible cardio-version,

advice re potent antiarrhythmic drug treatment or interventional EP procedures.

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SUMMARY AND TABLES

TYPE DESCRIPTION TREATMENT

First Attack Self limiting

No previous AF

None

RECURRENT AF

Paroxysmal Spontaneous termination

within 1-2 days ( seldom

attacks > 7 days )

Rate or Rhythm

control

Persistent Spontaneous termination

within 1-2 days ( seldom attacks

> 7 days )

Rate or Rhythm

control

Permanent AF Dominant rhythm Conversion not neededor not attempted

Rate control

THE 3 P CLASSIFICATION OF ATRIAL

FIBRILLATION

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Confirmed diagnosis of AF

Paroxysmal AF Persistent AF Permanent AF

Rhythm

control

Remains symptomatic * Rate

controlFailure of rhythm control

or

* The vast majority of patients will be managed by rate control, with or without anticoagulation

depending upon their RISK

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GRAMPIAN ATRIAL FIBRILLATION PATHWAY


Atrial Fibrillation Confirmed:

ECG FBC TFT’s, U+E’s LFT’s

ECHO cardiogram

RHYTHM CONTROL

(Small minority)

Discuss with or refer Cardiology

RATE CONTROL

(Vast majority)

Lenient Rate Control

if asymptomatic and HR

< 110 bpm on ECG

Strict Rate control

if symptomatic

ASSESS

THROMBO-EMBOLIC RISK

Significant structural including valvular heart disease

Non-valvular AF

CHA2DS2-VASc score ≥ 2

CHA2DS2-VASc = 1 and no other significant risk factors

CHA2DS2-VASc score 0 and no other significant risk factors

Warfarin Aspirin or Warfarin Aspirin or

nothing

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Old CHADS2 acronym Score

New CHA2DS2-VASc acronym Score

Congestive heart failure 1

Congestive heart failure/LV dysfunction 1

Hypertension 1 Hypertension 1

Aged ≥75 years 1 Aged ≥75 years 2

Diabetes mellitus 1 Diabetes mellitus 1

Stroke/TIA/TE 2 Stroke/TIA/TE 2

Maximum score 6

Vascular disease (prior MI, PAD, or aortic plaque) 1

Aged 65-74 years 1

Sex category (i.e. female gender) 1

____________ __

Maximum score 9

Patients with Valvular Heart Disease (under READ Code G54) should

be anti-coagulated regardless of the CHA2DS2-VASc score.

New CHA2DS2-VASc and older CHADS2 scores Old CHADS2 and newer CHA2DS2-VASc sores

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CLINICAL CHARACTERISTIC POINTS AWARDED

H Hypertension 1

A Abnormal liver/renal function 1-2

S Stroke 1

B Prior major Bleeding or predisposition 1

L Labile INR 1

E Elderly (>65) 1

D Drugs/alcohol concomitantly 1-2

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HAS-BLED SCORING SYSTEM

POINTS

H Hypertension SBP > 160mmHg 1

A Abnormal Renal Function

chronic dialysis, renal transplant, or serum creatinine ≥ 200 µmol/l

1

Abnormal Liver Function

chronic hepatic disease (eg. cirrhosis) or significant biochemical derangement ( bilirubin ≥ 2X upper limit of normal, in association with AST/ALT/Alk Phos ≥ 3X upper limit of normal)

1

S Stroke previous stroke/TIA 1

B Bleeding previous bleeding history +/or predisposition. (eg. bleeding diathesis, anaemia

1

L Labile INR unstable high INR or <60% within therapeutic range 1

E Elderly > 65 years 1

D Drugs/alcohol concomitant use of antiplatelet agents, NSAID’s etc 1-2

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grampian primary care atrial fibrillation guidelines 2010

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