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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 ………………………………………………………………………………….
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1.
E
MANAGING THE HEART RATE + / OR RHYTHM ……………………………………………………….
5
(a)
Rate Control ……………………………………………………………………………………………………..
6
(b)
Rhythm Control …………………………………………………………………………………………………
7
2.
REDUCING THE THROMBOEMBOLIC RISK ……………………………………………………………….
8
3.
ESTIMATING THE BLEEDING RISK …………………………………….........…………………………….
10
4.
IDENTIFYING AND TREATING THE UNDERLYING CAUSE…………………………………………..
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SUMMARY AND TABLES ……………………………………………………………………………………………….. .
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Grampian Primary Care Atrial Fibrillation Guidelines 2010
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Grampian Primary Care Atrial Fibrillation Guidelines 2010
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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
TYPE
First attack
:
The 3 P’s
DESCRIPTION
TREATMENT
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 antiarrhythmic 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 C
SCORE
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 Grampian Primary Care Atrial Fibrillation Guidelines 2010
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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 7 days )
Persistent
Permanent
Spontaneous termination within 1-2 days ( seldom attacks > 7 days )
AF Dominant rhythm Conversion not needed or not attempted
Grampian Primary Care Atrial Fibrillation Guidelines 2010
Rate or Rhythm control
Rate control
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Confirmed diagnosis of AF
Paroxysmal AF
Persistent AF
Permanent AF
or
Rhythm control
Remains symptomatic Failure of rhythm control
* Rate control
* The vast majority of patients will be managed by rate control, with or without anticoagulation depending upon their RISK
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Atrial Fibrillation Confirmed: ECG FBC TFT’s, U+E’s LFT’s ECHO cardiogram
RHYTHM CONTROL
RATE CONTROL
(Small minority)
(Vast majority)
Discuss with or refer Cardiology
Strict Rate control
Lenient Rate Control
if symptomatic
if asymptomatic and HR < 110 bpm on ECG
ASSESS THROMBO-EMBOLIC RISK
Significant structural including valvular heart disease
Non-valvular AF
CHA2DS2-VASc = 1 and no other significant risk factors
CHA2DS2-VASc score 0 and no other significant risk factors
CHA2DS2-VASc score ≥ 2
Warfarin
Aspirin or Warfarin
Grampian Primary Care Atrial Fibrillation Guidelines 2010
Aspirin or nothing
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Patients with Valvular Heart Disease (under READ Code G54) should be anti-coagulated regardless of the CHA2DS2-VASc score.
Old CHADS2 and newer CHA2DS2-VASc sores New CHA2DS2-VASc and older CHADS2 scores
Old CHADS2 acronym
Score
Congestive heart failure
1
Hypertension
1
Aged ≥75 years
1
Diabetes mellitus
1
Stroke/TIA/TE
2
Maximum score
6
New CHA2DS2VASc acronym Congestive heart failure/LV dysfunction
Score
1
Hypertension Aged ≥75 years Diabetes mellitus
1
Stroke/TIA/TE Vascular disease (prior MI, PAD, or aortic plaque) Aged 65-74 years Sex category (i.e. female gender)
2
____________
__
Maximum score
9
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1 1
1
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CLINICAL CHARACTERISTIC
H A S B L E D
Hypertension Abnormal liver/renal function Stroke Prior major Bleeding or predisposition Labile INR Elderly (>65) Drugs/alcohol concomitantly
POINTS AWARDED 1 1-2 1 1 1 1 1-2
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HAS-BLED SCORING SYSTEM POINTS H A
S
Hypertension Abnormal Renal Function Abnormal Liver Function Stroke
SBP > 160mmHg chronic dialysis, renal transplant, or serum creatinine ≥ 200 µmol/l
1 1
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
previous stroke/TIA 1
B
Bleeding
previous bleeding history +/or predisposition. (eg. bleeding diathesis, anaemia
L Labile INR E Elderly D Drugs/alcohol
1
unstable high INR or 65 years
1
concomitant use of antiplatelet agents, NSAID’s etc
1-2
MAXIMUM
9
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