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Atrial Fibrillation UpdateDon’t Miss a Beat
ACEP2016
Corey M. Slovis, M.D.Vanderbilt University Medical Center
Metro Nashville Fire DepartmentNashville International Airport
Nashville, TN
VanderbiltEM.com
Atrial Fibrillation is Common
• # 1 sustained cardiac arrhythmia
• > 3,000,000 patients
• 1% of US population
• 9% of all those ≥ 80 yo
• AFib ED visits 33% in past 5 years
JAMA 2001;285:2370-75
JAMA 2001;285:2370-75
5 Step ED Dx - Rx
• Secure ABCs, with rate control if needed
• Beta Blocker vs Diltiazem
• Determine etiology
• Establish stroke risk (CHA2DS2-VASc)
• Cardiovert, admit or D/C on meds
Pericardium
5 Causes of Atrial Fibrillation
Myocardium
Endocardium
Pulmonary
Hypersympathetic
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There Are 5 Causes of Atrial Fibrillation
• Pericardium
• Myocardium
• Endocardium
• Pulmonary
• Hypersympathetic
Pericarditis
LVH, Myocarditis
Endocarditis, valvulardisease
PE, pulmonary hypertension
Cocaine, amphetamines, hyperthyroid, ETOH withdrawal, caffeine, beta agonists, fever, dehydration
Paroxysmal
5 Types of Atrial Fibrillation
Persistent
Long Standing
Loan AF
Recurrent
There Are 5 Types of Atrial Fibrillation
• Paroxysmal
• Persistent
• Long Standing
• Loan AF
• Recurrent
Terminates spontaneously < 7 days
> 7 days of continued AF
1 year or more
No risk factors and < 60
Repeated episodes often subclinical and not recognized
There Are 5 Routine Tests for All New AF Patients
• CBC
• BMP
• Thyroid
• CXR
• Echocardiogram (sooner or later)
Consider Additional Tests
• BNP
• Troponin
• Exercise Testing
R/O HF
R/O ACS
WPW, Inducible, ACS
Afib = Stroke Risk
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Atrial Fibrillation Equals an Increased Stroke Rate
• About 0.5-1% per year but can be higher
• 5% if no anticoagulation
• CHA2DS2-VASc – important determinant
• Silent cerebral ischemia by CT/MRI is 20-40%
• AF doubles risk of death from age 55 onward (2.2/1.42 F/M)
Always Calculate the Patient’s ScoreCHA2DS2-VASc
• CHF (1)
• Hypertension (1)
• Age ≥ 75 (2)
• Age 65 – 74 (1)
• Diabetes Mellitus (1)
• Stroke/ TIA/Thromboembolic (2)
• Vascular DSX (AMI, PVD, Aortic Plaques (1)
• Sex Female (1)
Chest 2010;137:263-272
0123456789
10111213141516
0
1.3
0 1 2 3 4 5 6 7 8 9
3.2 4.0
Stroke Risk and CHADS2 Score
9.8
6.7
15.2
2.2
6.7
9.6
JAMA 2001;285:2370-75
Alliance for Aging Research: Stroke prevention in AF; 2015
JACC 2016;68:525-68
Stroke Is The Biggest AF Risk
• 5% year if no anticoagulation
• 10% year if prior CVA or TIA
• Anticoagulation decreases CVA risk by at least 2/3
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Rate vs Rhythm Control
• Classic article, 4,060 pts, multicenter
• Average age 70 yo ± 9
• Rate controlled patients had less hospitalizations
• More adverse effects in the rhythm group
• Slightly more deaths too (p = ns; 0.08)
NEJM 2002;347:1825-37
In General: Rate Control is Superior to Rhythm Control
But maybe rate control is not always best for some ED patients
Annals of Emerg Med 2015;65:540-2
• Meta-analysis of 4 ED relevant studies
• 1438 patients with new onset AF
• Rate control if older, chronic AF
• Rhythm > rate control if < 65 yo and healthy
ED Rate vs. Rhythm Control
Younger, healthier patients do better with therapy directed at keeping them
in sinus rhythm
Older, sicker patients do better with their AF rate controlled
Rhythm Control
Rate Control
5 Step ED Dx - Rx
• Secure ABCs, with rate control if needed
• Beta Blocker vs Diltiazem
• Determine etiology
• Establish stroke risk (CHA2DS2-VASc)
• Cardiovert, admit or D/C on meds
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Rate Control in AF• Calcium Channel Blockers
- Diltiazem 25 mg over 1-2 minMay to 35 mg over1-2 min if inadequate response after 5 min
• Beta Blockers- Metoprolol 5 mg IV q 5 min
up to 3 doses
- Esmolol 0.5 mg/kg over 1 min0.05 – 0.1 mg/kg/mintitrate to effect
• Although cardiologists seem to prefer Metoprolol, Diltiazem is as good or better for AF with RVR
• No increased toxicity
• Be careful with dosing
• Older, frailer patients should get less
Rate Control for AF with RVRTake Homes
European Heart 2013;34:1481-88; 1489-97
• The role of Digoxin in Atrial Fibrillation is controversial – it may increase mortality or be a marker for those who will do badly regardless of its use
• In general – don’t be the one to start it
ED Rhythm Control
Cardioversion of Atrial Fibrillation
Safety of ED Cardioversion
• Very safe if no thrombus
• Risk of CVA increases over time
• TEE required if onset unknown or > 48 hrs
• New evidence suggests maybe > 12 hrs
JAMA 2014;312:647-8
0.00.10.20.30.40.50.60.70.80.91.01.11.2
< 12 12-24
0.3%
1.1%
OR=4.0
Risk of CVA S/P Cardioversion without anticoagulants0-48 hrs onset = 0.7% JAMA 2014;312:647-8
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ED Conversion of Atrial Fibrillation
• Medical followed by electrical
• Medication is effective in about 50%-80%
• Electricity is 86%-90% effective
• Not if significant underlying disease(HF, pneumonia, ACS, etc.)
• Must be less than 48 hrs of AFib
Annals Emerg Med 2011;58:517-20
Annals Emerg Med 1999;33:379-87
• 289 stable patients, new onset Afib
• Included patients with AF > 48 hrs (51/289)
• Excluded unstable patients
• Excluded underlying illness requiring admission
• Average age 64 ± 14; HR 125 ± 26
• Used Procainamide (180 pts, 62% of total)
• 500 mg then, if needed, to 1,000 mg
• 50% converted pharmacologically
• 500 mg converted 44%, 56% took 1,000 mg
• Not if prolonged Q-T or Hypotensive
Pharmacological CardioversionAnnals Emerg Med 1999;33:379-87 • This study made ED conversions for
new onset AF a viable practice option
• It is common in Canada and variable in USA
• Many centers do a cardiologist-performed TEE before cardioversion
Am J Emerg Med 2016;34:1486-90
• 236 consecutive Austrian AFib pts
• All with AFib with onset < 48 hrs
• Average age 66.8 ± 11.8; 30 day follow up
•CHA2DS2VASC ≥ 2 in 80%!!
•Mainly used ibutilide, vernakalant and flecainide
How safe and effective is pharmacological cardioversion of Atrial Fibrillation?
• All anticoagulated with LMWH pre-medication
• 72.5% converted with first medication
• Same efficacy for Ibutilide, Vernakalant and Flecainide
• One stroke within 30 days
ResultsAm J Emerg Med 2016;34:1486-90
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• 68 pts with 79.4% effectiveness
• 2.1% toxicity; 1 hypotension, 1bradycardia, 1 AMS
• A new potential non-electrical effective therapy
Vernakalant ResultsAm J Emerg Med 2016;34:1486-90
Electrical Conversion
• AHA recommends 120-200J biphasic
• 50-100J for flutter
• My bias: Use highest recommended
• AP or AL – your choice
• Switch positions if unsuccessful
Cardioversion for Fib/Flutter
Acad Emerg Med 2014; 21:717-26
• Meta-analysis 13 studies
• 836 AP pts vs 856 AL pts
• Trend toward AL > AP if biphasic
Neither A-P nor A-L Pad Placement is Superior
• TEE all others
• If no TEE = 3 weeks pre cardioversion
Anticoagulation Pre Cardioversion
If CHA2DS2-VASc = 0 not needed pre or post
• Transesophageal (TEE) not Transthoracic
• Used to R/O thrombus pre cardioversion
• Mandatory if sx > 48 hrs or unknown
• May be used if > 12 hrs or older pts
• Not required in younger healthy pts if onset is acute and heralded by specific symptoms
Who Needs an Echo in AF
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Annals Emerg Med 2011;58:517-20
“We conclude that it would be within the standard of care to discharge home stable
patients with AFib after cardioversion with adequate follow-up”...“The return rate for
relapsed AFib is 3%-17%”
JACC 2016;68:525-68
• 0
• 1
• 2
• 0
• NOAC or discuss
• NOAC or Warfarin
JAMA 2015; 314:291-2
CHA2DS2-VASc Agent JACC 2015;65:643-4
• Increasing evidence for anticoagulation if CHA2DS2-VASc = 1
• Yearly strokes = 2.75% (m), 2.55% (f)
• Incremental risk if age 65-74
• Do not D/C unless you, patient and cardiologist have all agreed on plan
NOACs now endorsed in ACC/AHA guidelines.
Check carefully for use/dosage in CRF, valvular disease, obese,
fluid and s/p cardioversion
NOACs, DOACsNovel Oral AnticoagulantsDirect Oral Anticoagulants
• Apixaban
• Dabigatran
• Edoxaban
• Rivaroxaban
Eliquis anti-xa
Pradaxa direct antithrombin
Savaysa anti-xa
Xaralto anti-xa
Apixaban
Dabigatran
Edoxaban
Rivaroxaban
Eliquis anti-xa
Pradaxa direct antithrombin
Xaralto anti-xa
Savaysa anti-xa
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BMJ 2016;353:i2868
Is apixaban safer than warfarin in complicated patients on multiple other medications?
• 18,201 Afib pts, apixaban vs warfarin
• Divided pts into ≤ 5 drugs, 6-8, ≥ 9 drugs
• Average age 69
• Converted with 3 mg/kg of vernakalant over 10 min
• More drugs = worse outcomes
Stroke or Systemic Embolism
Major Bleeding NOAC vs WarfarinTake Homes
• 21% less strokes with apixaban(1.27 % per yr vs 1.60%)
• 31% less major bleeding(2.13% per yr vs 3.09%)
• 11% lower mortality(3.52% / yr vs 3.94%)
Older pts with Atrial Fibrillation will have increased morbidity & mortality…but higher
with warfarin than a NOAC
Warfarin use is decreasing and is becoming relegated to mainly those
patients with:
Mechanical Heart Valves
Mitral Stenosis
Chronic Renal FailureLancet 2014;383:955-62
Anticoagulation for AFib• Warfarin:
• Apixaban:
• Edoxiban:
• Dabigatran:
• Rivaroxaban:
INR 2-3; not < 2
5 mg BID2.5 mg BID < 60 kg, > 80 y, Cr > 1.5
60 mg QD > 60 kg30 mg QD > 30 kgNot for pts CrCl > 95
150 mg BID if CrCl > 30
20 mg / d15 mg / d if CrCl 30-49
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• Two populations: CHADS2 ≥ 2 and CHADS2VASC ≥ 2
• 38.2% of 210,380 CHADS2 ≥ 2 got only ASA
• 40.2% of 294,642 Chads2VASC ≥ got only ASA
JACC 2016;67:2913-23
How often do we not follow current recommended anticoagulation guidelines for
high risk Afib patients?
• More than 1 in 3 high risk for stroke AF pts treated below the standard of care!
Anticoagulation and ED Discharge
Annals Emerg Med 2013;62:557-65 Annals Emerg Med 2013;62:566-8
Annals Emerg Med 2015;65:1-12 Annals Emerg Med 2015;66:347-54
• EM MDs need to pay close attention to CHA2DS2-VASc scores
• Anticoagulants started in ED increase compliance and decrease stroke risk
• Don’t discharge patients without considering the need to begin anticoagulation
Should you always provide rate control in borderline sick patients
with Atrial Fibrillation?
Annals of Emerg Med 2015;65:511-22
Is rate control for atrial fibrillation always the best strategy?
• 416 patients with AF
• All patients had “complex” AF
• Complex = an acute underlying illness
• 2 Canadian University affiliated EDs
Annals of Emerg Med 2015;65:511-22
• Shock requiring vasopressors
• Intubation or NIPPV
• Bradycardia requiring pacing or meds
• Stroke or embolic complication
• CPR or death
Major Complications
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0%
10%
20%
30%
40%
50%
Rate or RhythmControl
Attempted
No Rate orRhythm Control
40.7%
7.1%
Major Adverse Complications Annals of Emerg Med 2015;65:511-22
33.6% absolute differenceRR=5.7
0%1%2%3%4%5%6%7%8%9%
10%11%12%13%14%15%
Rate or RhythmControl
Attempted
No Rate orRhythm Control
14.1%
19/135
1.1%
3/281
Total Adverse Events Annals of Emerg Med 2015;65:511-22
13% absolute differenceRR=11.7
0%
10%
20%
30%
40%
50%
ControlAttempted
No Attempt atControl
19.0%
44.5%
Effective Rate Control (> 20 BPM)Annals of Emerg Med 2015;65:511-22
(Elec, D;1+, BB) (Crystalloid, Bronchodilator)
25.5% absolute differenceRR=2.3
Annals of Emerg Med 2015;65:511-22
• 60% (9/15) had cardiovascular complications
• 26.7% (4/15) had medication complications
• 19.0% had pulse reduction of 20 BPM with medical control
• 20% (3/5) had successful electrical conversion
Complication Rate vs. Effectiveness
Trying to Control AF in Sick PatientsTake Homes
• Rarely effective
• Dangerous
• Focus on underlying disease before attempting to control rate or rhythm
In Closing
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AF Rate Control in Complex PatientsTake Homes
• Treat the underlying disease(s)
• It’s dangerous to try to control rate immediately
• Beware underlying sepsis, dehydration, HF
• Beta blockade + HF = ETI
Older pts and higher CHADS2 scores often denote who has an underlying cause of AF with RVR
JACC 2014;64:2246-80
• Definitive recommendations from AHA-ACC
• 201 references, up to 2014
• Every possible table & resource
The Best Single Current Cardiology Reference
Annals of Emerg Med 2015;65:532-9
• Authoritative review
• ED focused
• 48 references including from 2015
The Best Single Current EM Reference
Always Calculate the Patient’s ScoreCHA2DS2-VASc
• CHF (1)
• Hypertension (1)
• Age ≥ 75 (2)
• Age 65 – 74 (1)
• Diabetes Mellitus (1)
• Stroke/ TIA/ Thromboembolic (2)
• Vascular DSX (AMI, PVD, Aortic Plaques (1)
• Sex Female (1)
Chest 2010;137:263-272
5 Step ED Dx - Rx
• Secure ABCs, with rate control if needed
• Beta Blocker vs Diltiazem
• Determine etiology
• Establish stroke risk (CHA2DS2-VASc)
• Cardiovert, admit or D/C on meds
NOACs are here
Become expert in using one
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Atrial Fibrillation is common
Summary
Stroke is high risk
Always calculate CHA2DS2-VASc score
Anticoagulate if indicated
2 = yes, 0 = no, 1 = yes or discuss
Treat underlying conditions
Summary
Dilt or BB for rate control
Cardioversion can be safe < 12-48 hrs
Antiarrhythmics convert 50-80%
200 Joules biphasic works 90%
VanderbiltEM.com