Atrial Fibrillation Steve McGlynn Specialist Principal Pharmacist (Cardiology), Greater Glasgow and Clyde Honorary Clinical Lecture, University of Strathclyde.

Atrial Fibrillation

Steve McGlynn

Specialist Principal Pharmacist (Cardiology),

Greater Glasgow and Clyde

Honorary Clinical Lecture,

University of Strathclyde

Some types of arrhythmia

Supraventricular Sinus Nodal

Sinus bradycardia Sinus tachycardia Sinus arrhythmia

Atrial Atrial tachycardia Atrial flutter Atrial fibrillation

AV Nodal AVNSVT Heart blocks

Junctional Ventricular

Escape rhythms Ventricular tachycardia Ventricular fibrillation

Atrial fibrillation

A heart rhythm disorder (arrhythmia). It usually involves a rapid heart rate, in which the upper heart chambers (atria) are stimulated to contract in a very disorganized and abnormal manner.

A type of supraventricular tachyarrhythmia

The most common arrhythmia

Aetiology

Rheumatic heart disease Coronary heart disease

(MI) Hypertension Myopericarditis Hypertrophic

cardiomyopathy Cardiac surgery

Thyrotoxicosis Infection Alcohol abuse Pulmonary embolism Caffeine Exercise

Lone AF

NHS QIS Clinical Standards Audit 2010: AF PREVALENCE IN SCOTLAND

NHS QIS Clinical Standards April 2010 - Heart Disease

NHS Board Residence (HB) Population with AFSubmitted Practices

PopulationPercentage (%)

  Numerator Denominator  

Ayrshire & Arran 1,512 112,292 1.3%

Dumfries & Galloway 483 29,581 1.6%

Fife 1,357 96,989 1.4%

Forth Valley 2,064 142,264 1.5%

Greater Glasgow & Clyde 9,625 673,305 1.4%

Highland 790 60,598 1.4%

Lanarkshire 1,700 129,339 1.3%

Lothian 1,354 98,918 1.3%

Orkney 69 4,189 1.4%

Shetland 138 9,849 1.6%

Tayside 237 12,617 1.4%

Western Isles 141 6,893 1.9%

SCOTLAND 19,470 1,376,834 1.4%

Classification

New / Recent onset < 48 hours

Paroxysmal variable duration self terminating

Persistent Non-self terminating Cardiovertable

Permanent Non-self terminating Non-cardiovertable

Symptoms / Signs

Breathlessness / dyspnoea

Palpitations Syncope / dizziness Chest discomfort Stroke / TIA

6 x risk of CVA 2 x risk of death 18 x risk of CVA if

rheumatic heart disease

Irregularly irregular pulse Atrial rate

300-600bpm Ventricular rate depends

on degree of AV block 120-160bpm Peripheral rate

slower (pulse deficit)

Investigations

Electrocardiogram (ECG) All patients May need ambulatory monitoring

Transthoracic echocardiogram (TTE) Establish baseline Identify structural heart disease Risk stratification for anti-thrombotic therapy

Transoesophogeal echocardiography (TOE) Further valve assessment If TTE inconclusive / difficult

Normal Sinus Rhythm

‘Fast’ AF

‘Slow’ AF

Investigations

Electrocardiogram (ECG) All patients May need ambulatory monitoring

Transthoracic echocardiogram (TTE) Baseline Structural heart disease Risk stratification for anti-thrombotic therapy

Transoesophogeal echocardiography (TOE) Further valve assessment TTE inconclusive / difficult

Diagnosis

Based on:

ECG Presentation Response to treatment

Treatment objectives

Rhythm / rate control

Stroke prevention

Treatment strategies

New / Recent onset Cardioversion Rhythm control

Paroxysmal Rate control or

cardioversion during paroxysm

Rhythm control if needed

Persistent Cardioversion Rhythm control Peri-cardioversion

thromboprophylaxis

Permanent Rate control Thromboprophylaxis

Pharmacological Options

Class Ic Anti-arrhythmics Flecainide / Propafenone Rhythm control May also be pro-arrhythmic

Class II Anti-arrhythmics Beta-blockers Mainly rate control Control rate during exercise and at rest Generally first choice Choice depends on co-morbidities

Class III Anti-arryhthmics Amiodarone / Dronedarone Mainly rhythm control May be pro-arrhythmic Concerns over toxicity

Class IV Anti-arryhthmics Calcium channel blockers (verapamil / diltiazem only) Rate control only Alternative to beta-blockers if no heart failure

Digoxin Rate control only Does not control rate during exercise Third choice unless others contra-indicated

Acute AF

Treatment will depend on:

History of AF Time to presentation (<> 24 hours) Co-morbidities (CHD, CHF/LVSD etc) Likelihood of success (History)

Rate Vs. Rhythm control

Rhythm control not feasible or safe Beta-blocker Verapamil Digoxin (CHF)

Rhythm control if possible and safe DC cardioversion (if possible) Amiodarone (CHD or CHF/LVSD) Flecainide (Paroxysmal AF)

Paroxymal AF

Rhythm control* Beta-blocker Class 1c agent or sotalol

If CHD - sotalol If LVD: Amiodarone

Dronedarone? Not if heart failure

*May be “Pill in the pocket”

Antithrombotic therapy as per risk assessment Aspirin 75-300mg warfarin to INR 2-3

See later

Persistent AF

Rhythm control Beta blocker No structural heart

disease: Class 1c* or sotalol

Structural heart disease: amiodarone

Rate control As for permanent AF

* not if CHD present

Antithrombotic therapy as per risk assessment

Pre-cardioversion thromboprophylaxis of at least 3 weeks

If rate control, as for permanent AF

Permanent AF

Beta blocker or Calcium channel blocker

and/or Digoxin

Amiodarone? Option if poor rate

control on above

Dronedarone? Increased mortality

Antithrombotic therapy as per risk assessment Aspirin 75-300mg Warfarin to INR 2-3

See later

Stroke prevention (non-rheumatic AF)

Stroke Risk Assessment (CHADS2)

C Chronic Heart Failure (1 point) H Hypertension (1 point) A Age > 75 years (1 point) D Diabetes (1 point) S Stroke, TIA or systemic embolisation (2

points)

Score < 2: low risk, aspirin* or anticoagulant Score ≥ 2: high risk, anticoagulant indicated

*Evidence for aspirin is weak

Stroke Risk Assessment (CHA2DS2VASc)

Alternative to CHADS2

C Chronic Heart Failure (1 point) H Hypertension (1 point) A Age > 75 years (2 points) D Diabetes (1 point) S Stroke, TIA or systemic embolisation (2 points) V vascular disease (1 point) A Age 65-74 years (1 point) Sc Sex category (1 point if female)

Score ≥2 = High risk – anticoagulate unless contraindicated

Bleeding Risk Assessment(HAS-BLED)

1 point each for: Hypertension Abnormal renal/liver function (1 for each) Stroke Bleeding history or predisposition Labile INR Elderly (age over 65) Drugs*/alcohol** concomitantly (1 for each)

*Drugs that increase bleeding, e.g. aspirin

** Alcohol excess

Anticoagulants

Warfarin remains standard anticoagulant at present

3 new oral anticoagulants Dabigatran (Direct thrombin inhibitor)

Licensed by MHRA Approved by SMC

Rivaroxiban (Factor Xa inhibitor) Licensed by MHRA

Apixaban (Factor Xa inhibitor)

Fixed doses No monitoring At least as effective as warfarin Safer than warfarin? Dabigatran capsules not stable outside of original blister Very difficult to reverse effect unlike warfarin Much more expensive (even allowing for INR costs) Place in therapy not clear yet

Dabigatran Consensus

NHS in Healthcare Improvement Scotland Working Group:National consensus on dabigatran

The consensus statement states that:

on balance of risks and benefits, warfarin remains the anticoagulant of clinical choice for moderate or high risk atrial fibrillation patients (CHA2DS2-VASc ≥ 2) with good INR control, and

clinicians should consider prescribing dabigatran in patients with:

poor INR control (less than 60% of time in INR range) despite evidence that they are complying, or

allergy to or intolerable side effects from coumarin anticoagulants.

http://www.healthcareimprovementscotland.org/default.aspx?page=13900

Conclusions

AF is a common condition. Patients may be unaware of its presence and are

therefore at risk of a stroke Effective treatment strategies exist to control

symptoms Effective treatment strategies exist to reduce the

risk of stroke Patient education and choice are central to

improving the likelihood of treatment success