Transcript Atrial Fibrillation - Guildford and Waverley CCG

Atrial Fibrillation
Dr Avinash Haridas Pillai
Background
Most common sustained cardiac
arrhythmia
 Prevalence 0.5-1% in general population
 It is characterised by an ECG:
◦ Lacking any consistent p waves
◦ Irregular ventricular rate
Classification
1.
2.
3.
4.
5.
6.
7.
1st detected vs.. Recurrent
Self terminating vs.. Not self terminating
Symptomatic vs... Asymptomatic
Paroxysmal (self terminating within 7 days)
Persistent (if cardioverted to SR by any means
or last >7 days regardless of how it terminates)
Permanent (does not terminate or relapses
within 24 hrs of cardioversion)
Lone (in the absence of structural heart
disease) vs... Idiopathic (in the absence of any
disease)
Common Causes
Hypertension
 Left Ventricular Failure
 Coronary Artery Disease
 Mitral/Tricuspid Valve Disease
 HOCM

Symptoms
Palpitations
 Dyspnoea
 Fatigue
 Syncope
 Chest Pain
 30% present with AF as incidental finding

Signs

Irregular Pulse
◦ Faster at apex than at wrist
Variable intensity of 1st HS
 Absent “a” wave in the JVP

Investigations
ECG
 CXR
 Bloods

◦ FBC, UE, Cardiac Enzymes, TFT, LFT
◦ Mg, Ca2+
Echo
 24 hr tape/ETT/Angiogram

Management
Make a diagnosis
 Decide on rate or rhythm control
strategy
 Stratify stroke risk and consider
thromboprophylaxis

Rate vs. Rhythm control
Rate control

Rate control first if:◦ over 65
◦ with CHD (the vast majority)

Medication options:◦ Beta-blocker or Calcium Antagonist
(Verapamil/Diltiazem)
◦ If still no better then add in Digoxin
Rhythm control

Refer for rhythm control (cardioversion)
if:◦ Symptomatic with congestive heart failure
◦ Younger
◦ Unable to achieve adequate
Bleeding risk with Warfarin
Over 75
 NSAIDs
 Past Hx of bleeding
 Polypharmacy
 Uncontrolled BP
 On other antiplatelets

Stroke risk stratification
Stroke risk stratification and
thromboprophylaxis

Low
◦ Under 65 and no risk factor
◦ Aspirin if no contraindications

Moderate
◦ Over 65 and no risk factors
◦ Under 75 with risk factors
◦ Aspirin vs. Warfarin

High
◦ Previous ischaemic event/TIA
◦ Over 75 with risk factors; valve disease or heart
failure
◦ Warfarin if no contraindications
Annual Risk of Stroke
Risk Group
No Rx
Aspirin
Warfarin
Very High
(prev CVA/TIA)
12%
10%
5%
High
5-8%
4-6%
2-3%
Moderate
3-5%
2-4%
1-2%
Low
1.2%
1%
0.5%
CHADS2
Condition
Points
C
Congestive Heart Failure
1
H
BP more than 160mmHg
Or Treated BP
1
A
Age > 75
1
D
Diabetes
1
S2
Prior stroke/TIA
2
CHADS2
Score Annual Stroke
Risk %
Risk
Therapy
Range
75- 300 mg
0
1.9%
Low
Aspirin
1
2.8%
Moderate
Aspirin/Warfarin
2/>
4.0% >
High
Warfarin
INR 2-3
Paroxysmal AF

Thromboprophylaxis
◦ Just the same

Rhythm drugs
◦
◦
◦
◦
Standard B Blocker vs.. Pill in Pocket
Sotolol vs.. Class 1c agents
Amiodarone
Referral to EPS specialist
Atrial Flutter
Same antithrombotic Rx as AF
 Re-establish SR

◦ Cardiovert (Medication/DCCV)
◦ Pacing
Papers

Mixed comparison of stroke prevention
treatments in patients with nonrheumatic AF – Arch Int Med
2006:166:1269
◦ Warfarin more effective than Aspirin in
reducing stroke in AF
◦ Warfarin: will prevent 28 strokes at the cost
of 11 major bleeds
◦ Aspirin: will prevent 16 strokes at the cost of
6 major bleeds
Papers

Comparison of Warfarin vs. AspirinClopidogrel in AF Lancet 2006:367:1903
◦ Warfarin is superior to dual antiplatelet
therapy
Papers

BAFTA study 2007: Warfarin vs. Aspirin in
an elderly, community population. Lancet
2007:370:493
◦ Support the use of Warfarin over Aspirin in
patients over 75 unless there are
contraindications
Papers

ACTIVE A Trial NEJM 2009;360:2066
◦ Neither regime as effective as Warfarin
 Warfarin 1.1-1.3%
 Aspirin 3.3%
 Aspirin + Clopidogrel 2.4%
◦ Conclusion: In patients with moderate to high
risk of stroke in whom Warfarin is unsuitable,
the combination of Clopidogrel + Aspirin will
be most likely to provide NET clinical benefit
Papers

The ATHENA Study. NEJM 2009:360:668
◦ Primary outcome occured in 32% of the
Dranadone group vs. 39% of the placebo
(ARR of 7% = NNT 14)
◦ Significant reduction in CV deaths (2.7% vs.
3.9%)
Papers

Aspirin + Warfarin in patients with AF and
vascular disease BMJ2008:336:614
◦ If a patient taking Aspirin for a CVA develops
AF
 stop Aspirin
 start Warfarin
Questions
Summary
Haemodynamically Stable
 Cause
 Rate vs. Rhythm
 Bleed risk
 Stroke risk stratification
 Thromboprophylaxis
