Transcript Managing Atrial Fibrillation - Scioto County Medical Society

Current Mangement of Atrial Fibrillation:
An Evidence-Based Approach
John D. Hummel, MD
Ohio State University Medical Center
Ross Heart Hospital
Columbus, Ohio
Learning Objectives
• Understand the guidelines for
anticoagulation and where there is
latitude for physician decisionmaking.
• Be able to discriminate between
patients requiring restoration of sinus
rhythm vs. rate control alone.
• Be able to determine when patients
should be evaluated for curative
ablation.
Projected Number of Adults With
AF in the US: 1995 to 2050.
Adults with AF, MM
6
5
4.78
5.16
5.42 5.61
4.34
4
3.80
3
2
2.08
2.26
2.44
2.66
2.94
3.33
1
Year
Go A, et al. JAMA. 2001;285:2370-2375.
20
60
20
50
20
45
20
40
20
35
20
30
20
25
20
20
20
15
20
10
20
05
20
00
19
95
0
Atrial Fibrillation:
Costs to the Health Care System
ALOT!!
35% of arrhythmia hospitalizations
Average hospital stay = 5 days
Mean cost of hospitalization = $18,800
Does not include:
Costs of outpatient cardioversions
Costs of drugs/side effects/monitoring
Costs of AF-induced strokes
Estimated US cost burden 15.7 billion
Classification of Atrial Fibrillation
ACC/AHA/ESC Guidelines
First
Detected
Paroxysmal
(Self-terminating)
Persistent
(Not self-terminating)
Permanent
DIAGNOSTIC WORKUP
•
•
•
•
•
•
•
•
•
•
Minimum Evaluation
History and physical – Sx with AF, CV dz
Electrocardiogram – WPW, BBB, LVH, MI
Echocardiogram – LVH, LAE, EF, Valve Dz
Labs – TSH, Renal fxn, LFTs
Additional Testing
ETT – CAD, Exercise induced SVT / AF
Holter / Event Monitor – Confirm AF and Sxs
TEE – LA clot
EPS – SVT triggered AF
AHA / ACC / ECS Guidelines 2006
AF: TREATMENT OPTIONS
Rate control
Pharmacologic
• Ca2+ blockers
• -blockers
• Digitalis
• Amiodarone
Nonpharmacologic
• Ablate and pace
Prevent remodeling
Maintenance of SR
Pharmacologic
Class IA
Class IC
Class III
-blocker
ACE-I
ARB
Adapted from Prystowsky, Am J Cardiol. 2000;85:3D-11D.
Stroke prevention
Nonpharmacologic Pharmacologic
• Warfarin
• Thrombin inhibitor
• Aspirin
Catheter ablation
Surgery (MAZE)
Pacing
Nonpharmacologic
• Removal / isolation
LA appendage
Risk Factors for Thromboembolism in AF
High-Risk Factors
Previous CVA / TIA / Embolism
Mitral Stenosis
Prosthetic heart valve
Moderate-Risk Factors
Age > 75 yrs
HTN
CHF
DM
EF < 35%
Weaker-Risk Factors
Female
CAD
Thyrotoxicosis
Age 65 – 74 yrs
AHA / ACC / ECS Guidelines 2006
Recommended Therapy
High-risk factor or > 2
moderate-risk factors
Coumadin INR 2-3
(mechanical valve INR > 2.5)
1 moderate-risk factor
ASA or Coumadin
No risk factors
ASA 81-325mg daily
AF THERAPY
ANTITHROMBOTIC RX
AND
RHYTHM
CONTROL
OR ?
RATE
CONTROL
AFFIRM Trial: Rate vs Rhythm Control
Management Strategy Trial
• Design
– 5-year, randomized, parallel-group study
comparing rate control vs. AARx attempt at NSR
– Primary endpoint: overall mortality
• Patient population
–
–
–
–
–
–
4060 patients with AF and risk factors for stroke
Mean Age = 69 yo
Hx of hypertension: 70.8%
CAD: 38.2%
Enlarged LA: 64.7%
Depressed EF: 26.0%
The AFFIRM Investigators. N Engl J Med. 2002;347:1825-1833.
AFFIRM: All-Cause Mortality
30
Rate
Rhythm
25
Mortality, %
20
p=0.078 unadjusted
15
p=0.068 adjusted
10
5
0
0
1
2
3
Rhythm N:
2033
1932
Time (years)
1807
1316
Rate N:
2027
1925
1825
The AFFIRM Investigators. N Engl J Med. 2002;347:1825-1833.
1328
4
5
780
255
774
236
AFFIRM: Adverse Events
Rate
Rhythm
Ischemic stroke
77 (5.5%)*
80 (7.1%)*
INR < 2.0
27 (35%)
17 (21%)
Not taking
warfarin
25 (32%)
44 (55%)
* p=0.79
The AFFIRM Investigators. N Engl J Med. 2002;347:1825-1833.
AF Rate vs. Rhythm Control Trials:
Implications
• AFFIRM has demonstrated that rate control is
an acceptable primary therapy in a selected
high-risk subgroup of AF patients
• Continuous anticoagulation seems warranted
in all patients with risk factors for stroke
– Asymptomatic recurrences
Atrial fibrillation
Rate control – the problem:
Increased rates – more symptomatic, greater
hemodynamic impact.
Persistent increased rates – tachycardia induced
cardiomyopathy
Rate control – the goal:
PAF – control symptomatic tachycardia
Chronic afib – mean 24hr HR < 80-90 bpm
Atrial fibrillation
Rate control – Drug Therapy:
Digoxin – controls resting rate, OK in CHF patients .
Beta, Ca+2 blockers – controls resting and exercise
rates.
Best therapy – combination of beta blocker and
digoxin.
Even in the best of circumstances pacing support is
sometimes required
APPROACHES TO AF THERAPY
Rate control plus
anticoagulation preferred
•
•
•
•
•
•
No or lesser AF symptoms
Longer AF Hx
More SHD
Toxicity Risk
Elderly
Greater risk of
proarrhythmia
Rhythm control
preferred
•
•
•
•
•
Greater AF symptoms
Symptoms despite rate control
Younger age
No or lesser SHD
Rx option of class IC AAD
In anticoagulation candidates, continue anticoagulation indefinitely
Atrial Fibrillation
Length of time
in AF prior to
cardioversion
•
Duration of
AF is the best
predictor of
recurrent AF
after
cardioversion
Patients in sinus rhythm (%)
100
< 3 Months
3 - 12 Months
> 12 Months
80
60
40
*
20
0
*P = <0.02
Initial
Dittrich HC. Am J Cardiol. 1989;63:193-197.
One month
post-CV
Six months
post-CV
AF TREATMENT GOALS
• AF is rarely life-threatening and is
typically recurrent
• Treatment goals in symptomatic pts
–  frequency of recurrences
–  duration of recurrences
–  severity of recurrences
• Minimize risk of tachycardia induced
cardiomyopathy
• Safety is primary concern
Rhythm Control for AF: Commonly
Used Oral Antiarrhythmic Drugs
Class IA
Class IC
Class III
Quinidine
Propafenone
Sotalol
Procainamide
Propafenone SR
Amiodarone
Disopyramide
Flecainide
Dofetilide
Procainamide, disopyramide, and amiodarone are not FDA-approved for
treatment of AF.
Miller and Zipes. In: Braunwald, et al (eds). Heart Disease. 6th ed. 2001.
AF Efficacy:
Maintaining NSR > 6 Months
70
60
NSR, %
50
40
30
20
10
0
No
drug
Quin
Diso
Prop
Flec
Sot
Dof
Azim Amio
ORGAN TOXICITY
• Examples:
– Lupus, agranulocytosis, thrombocytopenia, optic
neuritis, pulmonary fibrosis, hepatitis, etc.
• Negligible:
– Dofetilide, flecanide, propafenone, sotalol
• Acceptible:
– Azimilide, disopyramide
• High:
– Amiodarone, procainamide, quinidine
Drug-Induced Proarrhythmia - Torsades
Factors Which Influence
Ventricular Proarrhythmia Risk
•
•
•
•
•
•
•
Hypokalemia, hypomagnesemia
Long QT at baseline
CHF / Decreased EF / Ventricular hypertrophy
Bradycardia
Female gender
Reduced drug metabolism or clearance
Amiodarone has lowest risk
Atrial fibrillation
Heart disease
Antiarrhythmic
None
Vagal afib
HTN
CAD
CHF/Substantial
LVH
IC
Disopyramide
IC (if no sig. LVH)
Sotalol
Amiodarone
Alternatives to Drug therapy
“Non-Pharmacologic Therapy”
Coumadin – LAA closure (Watchman)
Rate Control – AVN RFA + PCMK
AARx – Adjunctive AFL RFA
AARX – Curative Afib RFA
WATCHMAN® LAA
Filter System
Complete AVN ablation
Pacemaker Placement
AVN RF ablation
Objective Benefits of AV nodal Ablation
70
55
50
mean
54 + 7
60
mean
34 + 5
LVESD (mm)
LVEF (%)
45
50
mean
43 + 8
40
p < 0.001
30
40
mean
40 + 5
35
30
p < 0.003
25
20
20
Before
After
A Left ventricular ejection
fraction (%)
Rodriguez LM. Am J Cardiol. 1993;72:1137-1141.
Before
After
B Left ventricular end systolic
diameter (mm)
Complete AVN Ablation
Advantages:
100% efficacy
85% symptomatic improvement
Improved EF (LV remodeling)
Eliminates need for rate control drugs
Disadvantages:
Pacemaker dependant
Good Candidates:
Tachy / Brady Syndrome
PCMK in Place – CHF with BiV device
Medication refractory / intolerant
Elderly
60 F with PAF treated with Rythmol
Presented with recurrent tachycardia
Atrial Flutter Circuit
Atrial Flutter Circuit
Atrial Flutter Ablation
Atrial Flutter RFA
Atrial Flutter Ablation
Approximately 15% of AF patients treated with an AA
will develop AFL
Advantages:
95% efficacy
≈ 80% arrhythmia control if AARx continued
As primary Tx RFA more effective than AARx
Disadvantages: Invasive
Good Candidates:
Typical AFL (IVC / TV isthmus)
Primary AFL or AARx related AFL
Focal Origin of Atrial
Fibrillation
Hassaiguerre M, NEJM, 1998
• 94% of AF triggers
from Pulmonary
Veins
• “90 – 95% of all AF
is initiated by PV
ectopy”
RA
LA
SVC
17
31
FO
Pulmonary
Veins
6
IVC
CS
11
74 yo medically refractory AF, Echo – Normal
AA Rx - Verapamil, Rythmol, Betapace, Norpace
I
II
III
V1
RSPV
dist
RSPV
prox
LIPV
RA
*
Lasso Catheter
Circular Mapping & Ablation Catheter in
Right Superior Pulmonary Vein
Atrial Fibrillation Ablation
Atrial Shell and Cardiac MRI
45 yo F with medically refractory
Highly Symptomatic PAF
45 yo F with Medically Refractory PAF
CT Scan / Carto Images – PA View
45 yo with PAF
Conversion of AF to NSR, LSPV with AF
Abl
Lasso
LSPV
CS
Current State of Curative
Catheter-Based RFA
Procedural Success & Complications
• Total Patients > 800 (70% PAF)
• Expected success @ 1yr
– ≈ 70% after first procedure
– ≈ 80% after second procedure
• Complications ≈ 2 to 3%
–
–
–
–
–
Tamponade – 0.6%
Pulmonary vein stenosis – 0.6%
TIA / CVA – 0.5%
Esophageal-LA fistula - 0
Groin Bleeding / Hematoma
(Last 200 pts complications < 1%)
Atrial Fibrillation: Ablation vs Drug Rx.
Ablation
80% success
PV stenosis
AE fistula
TIA/CVA
Drug Rx.
50% success
Proarrhythmia
End Organ Toxicity
No Free Lunch
Torsades
AE fistula
PV stenosis
Current State of Curative
Catheter-Based RFA
Who is a good candidate?
Symptomatic / Frequent AF
Limited Heart Dz
EF > 35%
LA < 5.5cm
No MS / Rheumatic Dz
Younger Patients
No LA thrombus or Hx of CVA
Medically Refractory / Intolerant
(Ablation now second line therapy)
Industry Estimates: AF Demographics
• Approximately 26,000 AF
ablation procedures
(surgery + EP) were
performed in 2004.
•
•
AF Patients
Treated
(1%)
26,000
Currently, only about 1% of
AF population being
addressed with curative
therapies.
AF Patients
2,400,000
Estimates for EP Afib RFA:
2005 = 19,000
2006 = 21,000
AF Patients
AF Patients Treated
Physicians estimate apporx. 30% of Afib pts are RFA candidates.
Atrial Fibrillation Ablation
Evolution of the Moving Target
Esophageal
Fistulas
Left Atrial
Flutters
Tamponade
TIA/CVA
Early Rumors
(20 hr cases)
Mid 90’s
Left Sided Focal
IVUS / Transeptal
Right Sided Linear
WACA + Linear
Lasso
PV Isolation
Hybrid Approaches
3D Mapping CT integration
2006
Fractionated Egms
PV Stenosis
Phrenic Nerve
Injury
The Trouble With a Moving Target
Back to the
Right Side
Need for Stereotaxis,
Cryoablation, HIFU?
Atrial Fibrillation
New Technology Coming Your Patients Way at
Ohio State University
Stereotaxis – Magnetic Catheter Navigation
Energy Sources
High Intensity Focused Ultrasound (HIFU)
Cryoablation Balloon
Watchman – Left Atrial Appendage Closure
A-Fib vs. EP Labs