Transcript AFib Management and the Role of Catheter Ablation

AFib Management and the
Role of Catheter Ablation
Slide Kit Structure
Section I. AFib Overview
Section II. Clinical Management of AFib
Section III. Catheter Ablation for the
Treatment of AFib
Section I:
AFib Overview
Atrial fibrillation
• Atrial fibrillation (AFib) is a common disease
that causes the upper chambers of the heart
(atria) to beat rapidly and in an uncontrolled
manner (fibrillation).
• Uncoordinated, rapid beating of the atria
affects the flow of blood through the heart,
causing an irregular pulse and sometimes a
sensation of fluttering in the chest.
Classification of AFib Subtypes
Paroxysmal
Spontaneous termination
usually < 7 days and most often
< 48 hours
Persistent
Does not interrupt
spontaneously and needs
therapeutic intervention for
termination
(either pharmacological or
electrical cardioversion)
Permanent
AFib in which cardioversion is
attempted but unsuccessful, or
successful but immediately
relapses, or a form of AFib for
which a decision was taken not
to attempt cardioversion
Levy S, et al. Europace (2003) 5: 119
Prevalence of AFib
General population-based
prevalence
0.95%
2.5%
ATRIA study
Olmsted County study
Go AS, et al. JAMA (2001) 285: 2370
Miyasaka Y, et al. Circulation (2006) 114: 119
Prevalence of AFib in the General
Population in USA and EU
ATRIA
USA
2.8 million
Olmsted
7.4 million
( 300 million inhabitants)
EU
4.3 million
11.4 million
( 456 million inhabitants of 25 member states)
Prevalence of AFib
Projected number of persons with AF
(millions)
Olmsted County study
15.2
16
15.9
14.3
14
13.1
11.7
12
10.2
10
8.9
11.1
7.7
8
6 5.1
4 5.1
5.9
5.6
9.4
6.7
6.1
6.8
7.5
11.7
12.1
10.3
8.4
2
0
2000
2005
2010
2015
2020
2025
2030
2035
2040
2045
2050
Year
Miyasaka Y, et al. Circulation (2006) 114: 119
Incidence of AFib in the General
Population – Gender Differences
Olmsted County study
Observational period: 20 years
Men
0.49 %
Women
0.28 %
Ratio men to women = 1.86
Miyasaka Y, et al. Circulation (2006) 114: 119
Principal Reasons for Increasing
Incidence and Prevalence of AFib
1. The population is aging rapidly, increasing the pool
of people most at risk of developing AFib
2. Survival from underlying conditions closely
associated with AFib, such as hypertension, coronary
heart disease and heart failure, is also increasing
3. According to the Olmsted County study, the increase
is also related to the increasing population
4. These figures may also be significantly under-
estimated because they do not take into account
asymptomatic AFib (25% of cases in Olmsted
survey)
Miyasaka Y, et al. Circulation (2006) 114: 119
Steinberg JS, et al. Heart (2004) 90: 239
AFib has an Impact on All Aspects
of QoL
SF-36 quality of life scores in AFib patients and healthy subjects
SF-36 scale
AFib patients
(n=152)
Healthy controls
(n=47)
General health
54 ± 21
78 ± 17*
Physical functioning
68 ± 27
88 ± 19*
Role physical
47 ± 42
89 ± 28*
Vitality
47 ± 21
71 ± 14*
Mental health
68 ± 18
81 ± 11*
Role emotional
65 ± 41
92 ± 25*
Social functioning
71 ± 28
92 ± 14*
Bodily pain
69 ± 19
77 ± 15*
* p<0.001
Dorian P, et al. J Am Coll Cardiol (2000) 36: 1303
Risk Factors for AFib
ATRIA study
Characteristic
Diagnosed heart failure
Hypertension
(n=17,974)
29.2%
49.3%
Diabetes mellitus
17.1%
Previous coronary heart disease
34.6%
Baseline characteristics of 17,974 adults with diagnosed AFib,
July 1, 1996-December 31, 1997
Go AS, et al. JAMA (2001) 285: 2370
AFib is Responsible for 15-20% of
all Strokes
Cumulative stroke incidence (%)
– AFib is responsible for a 5-fold increase in the risk of
ischaemic stroke
12
8
Women AFib+
Men AFib+
Women AFib-
Men AFib-
4
0
1
2
3
4
5
1
2
3
4
5
Years of follow-up
Wolf PA, et al. Stroke (1991) 22: 983
Go AS, et al. JAMA (2001) 285: 2370
Friberg J, et al. Am J Cardiol (2004) 94: 889
Increased Risk of Cardiovascular
Events
Death or hospitalization in individuals with CV event(s) after 20
years
Men
100
Women
At least one CV event (%)
89
80
66
60
45
40
27
20
0
AFib
No AFib
AFib
No AFib
Stewart S, et al. Am J Med (2002) 113: 359
Mortality Associated with AFib
Framingham Heart Study, n=5209
Mortality during follow-up (%)
80
60
Men AFib+
Women AFib+
40
Men AFibWomen AFib20
0
0
1
2
3
4
5
6
7
8
9
10
Follow-up (y)
Benjamin EJ, et al. Circulation (1998) 98: 946
Incremental AFib Healthcare Costs
UK costs for AFib in 1995 vs. 2000
• 1995: Direct cost of AFib in the UK between £244 and £531
million (0.6–1.2% of overall health care expenditure)
• 2000: £459 million direct cost – double that in 1995 (0.9–2.4%
of NHS expenditure)
Cost of heart failure
admission
+50%
+48%
Cost of stroke
admission
+5.1%
warfarin use
10% admission
+7.4%
10% communitybased care
+5.6%
Base cost of AF
in 2000
0
100
200
300
400
500
600
700
Total health care expenditure (£ million)
Base cost
of AFib
Base cost of associated
conditions and
procedures
Incremental cost
of AFib
Other costs
Stewart S, et al. Heart (2004) 90: 286
Major Costs in Treatment of AFib
COCAF Study
8%
9%
2%
6%
52%
Hospitalizations
Drugs
Consultations
Further investigations
Paramedical procedures
Loss of work
23%
Le Heuzey JY, et al. Am Heart J (2004) 147:121
Cost of AFib (Europe)
FIRE study
• 4507 consecutive patients with AFib/flutter admitted to ER
enrolled in FIRE study (1.5%
admissions)
of all ER
• 61.9% of AFib/flutter patients were hospitalized (3.3%
all hospitalizations)
of
• Mean hospital stay 7+6 days
Santini M, et al. Ital Heart J (2004) 5: 205
The Burden of AFib
• AFib is responsible for significant economic and healthcare
costs
– Hospitalization costs
– Drug treatment
– Treatment of AFib-associated co-morbidities and
complications
• The health and economic impact will increase with the
increasing prevalence and incidence of AFib
• AFib, owing to its epidemiology, morbidity, and mortality,
represents a significant health problem with important social
and economic implications that needs greater attention and
allocation of more resources
Section II:
Clinical Management of
AFib
Primary Therapeutic Aims in AFib
• Restore and maintain sinus rhythm whenever possible
• Prevent thromboembolic events
In order to:
– Reduce symptoms and improve QoL
– Minimize impact of AFib on cardiac performance
– Reduce risk of stroke
– Minimize cardiac remodelling
ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation
J Am Coll Cardiol (2006) 48: 854
Treatment Options for AFib
Cardioversion
• Pharmacological
• Electrical
Drugs to prevent AFib
• Antiarrhythmic drugs
• Non-antiarrhythmic drugs
Drugs to control ventricular rate
Drugs to reduce thromboembolic risk
Non-pharmacological options
• Electrical devices (implantable pacemaker and defibrillator)
• AV node ablation and pacemaker implantation (ablate & pace)
• Catheter ablation
• Surgery (Maze, mini-Maze)
Recurrence Following
Cardioversion: AFFIRM Study
AFFIRM: most recurrences occur within 2 months
of cardioversion
Patients with AF Recurrence (%)
Treatment Arm
100
Rate control
Rhythm control
80
60
40
Log rank statistic = 58.62
p<0.0001
20
0
0
1
3
4
5
6
10, 481 (92)
73, 494 (75)
2, 484 (95)
18, 503 (79)
Time (years)
N, Events (%)
Rate control:
Rhythm control:
2
563, 3 (0)
729, 2 (0)
167, 383 (69) 96, 440 (80) 42, 472 (87)
344, 356 (50) 250, 422 (60) 143, 470 (69)
Raitt MN, et al. Am Heart J (2006) 151: 390
Amiodarone to Prevent Recurrence of
AFib
CTAF Study: mean follow-up 16 months
100
Patients without AFib (%)
p<0.001
80
60
40
Sotalol
20
0
0
Propafenone
Amiodarone
100
200
300
400
500
600
Follow-up (days)
Roy D, et al. N Engl J Med (2000) 342: 913
Effectiveness of Current AADs
• Even with the most effective AAD, such as
amiodarone, long-term efficacy is low
~50% or less at 1 year
Non-Pharmacological Treatment
Options for AFib
• Pacemakers not curative and must be worn for life
• Surgical procedures may be effective but are not a
practical solution for the millions of sufferers of AFib
• Catheter ablation is potentially curative
Devices
Electrophysiological
Surgery
Pacemaker
(single or dual chamber)
Internal atrial
defibrillators
Catheter ablation
AV node ablation
Maze procedure
Modified Maze
(mini-Maze)
ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation
J Am Coll Cardiol (2006) 48: 854
Management of AFib - Summary
• Current antiarrhythmic drug therapies are not highly
effective in maintaining sinus rhythm and generally
have poor outcomes
– high recurrence rates
– adverse effects and high discontinuation rate
• A potentially curative therapy for AFib is desirable
Section III:
Catheter Ablation for the
Treatment of AFib
Catheter Ablation
• Uses a series of long, thin wires (catheters) that
are inserted through an artery or a vein and then
guided through to the heart.
• One of the catheters is then used to localise the
source of the abnormal electrical signals and
another then delivers high energy waves that
neutralise (ablate) abnormal areas.
• Using catheters to reach the heart is a common
approach to treat a range of heart conditions and
is much less invasive than surgical treatments.
Landmarks in Catheter Ablation
Techniques
Technique
Maze reproduction
Publication date
Schwarz 1994
Right atrial linear lesions
Haïssaguerre 1994
Right and left atrial linear lesions
Haïssaguerre 1996
PV foci ablation
Jaïs / Haïssaguerre
1997/8
Ostial PV isolation
Haïssaguerre 2000
Circumferential PV ablation
Ablation of non-PV foci
Antral PV ablation
Double Lasso technique
CFAE sites ablation
Ostial or circumferential or antral PV
ablation plus extra lines (mitral isthmus,
posterior wall, roof)
Circumferential PV ablation with vagal
denervation
Pappone 2000
Lin 2003
Maroucche / Natale 2004
Ouyang / Kuck 2004
Nademanee 2004
Jaïs / Hocini 2004/5
Pappone 2004
1998: Ablation of PV Foci
Spontaneous Initiation of Atrial Fibrillation
by Ectopic Beats Originating in the
Pulmonary Veins
Haïssaguerre, M, Jaïs, P, Shah, DC, et al.
N Engl J Med (1998) 339: 659
• Pivotal study identifying the pulmonary veins as a
major source of ectopic electrical activity
• Radiofrequency ablation of ectopic foci was associated
with a 62% success rate (absence of recurrence at 8 
6m follow-up)
A Combination of Techniques may now
be used Depending on the Type of AFib
AFib
Trigger Ectopic Foci
PV & non-PV Foci
Ablation,
PV Isolation
Autonomic
Nervous
System
Vagal
Denervation
(parasympathetic
ganglia ablation)
Substrate Atrial tissue
CFAEs Ablation
Linear Lesions
(e.g. mitral isthmus,
roof)
Cardiac Imaging Techniques
• Electroanatomical mapping
– CARTO™ / CARTOMERGE™
• Fluoroscopy
• Angiography
• Intracardiac echography
• Cardiac spiral CT
• Cardiac MRI
CARTO™ System
– Localization of catheter to within 1 mm
– Increase safety margin during ablation
• 3D-electroanatomic maps (CARTO™) showing ablation points
encircling PVs
PV Antrum Isolation Guided by
CARTOMERGE™ Image Integration
Software Module
RUPV
LUPV
RMPV
LA
AC
RLPV
LLPV
Courtesy of Professor Antonio Raviele, Mestre, Italy
Catheter Visualization under
Fluoroscopic Guidance
Ablation
catheter
LAO
LASSO®
RAO
Efficacy and Safety of
Catheter Ablation
Meta-analysis of Catheter Ablation
Patients
Paroxysmal
AF
SHD
Linear
443
75%
26%
33%
55%
Focal
508
81%
35%
54%
71%
2,187
83%
36%
62%
75%
Circumferential
(all)
15,455
68%
37%
64%
74%
Circumferential
(LACA, WACA)
2,449
65%
37%
59%
72%
Circumferential
(PVAI)
11,132
68%
42%
67%
76%
559
51%
49%
75%
87%
23,626
61%
55%
63%
75%
Ablation method
Isolation
Substrate ablation
(CFAE)
TOTAL
6-month cure
6-months OK
Cure (by each author’s criteria) means no further AFib 6 months after the procedure in the absence
of AAD.
OK means improvement (fewer episodes, no episodes with previously ineffective AAD).
SHD indicates structural heart disease.
Fisher JD, et al. PACE (2006) 29: 523
Worldwide Survey on Efficacy and
Safety of Catheter Ablation for AFib
• Total success rate: 76%
• Of 8745 patients:
– 27.3% required 1 procedure
– 52.0% asymptomatic without drugs
– 23.9% asymptomatic with an AAD within <1 yr
• Outcome may vary between centres
Cappato R, et al. Circulation (2005) 111: 1100
Improved Survival with Ablation vs
Drug Treatment
• 589 ablated patients compared with 582 on AADs
Medical Group
Ablation Group
Survival probability (%)
100
90
80
Expected
Observed
70
60
One-sample log-rank test
Obs=36, Exp=31, Z=0.597, p=0.55
0
0
180
360
540
720
900 1080 0
Days of follow-up
One-sample log-rank test
Obs=79, Exp=341, Z=7.07, p<0.001
180
360
540
720
900
1080
Days of follow-up
Pappone C, et al. J Am Coll Cardiol (2003) 42: 185
More AFib-free Patients with Catheter
Ablation vs Drug Treatment
AFib-free
survival probability (%)
100
80
60
40
Ablation Group
Medical Group
20
0
0
100
Medical
300
Follow-up (days)
No. at risk
Ablation
200
589
507
479
379
282
217
135
582
456
354
277
207
141
97
Pappone C, et al. J Am Coll Cardiol (2003) 42: 185
Randomised Clinical Trials of Catheter
Ablation
RF ablation vs AAD as first-line treatment for
AFib
• Wazni OM et al. JAMA (2005) 293: 2634-2640
Catheter ablation in drug-refractory AFib
• Stabile G et al. Eur Heart J (2006) 27: 216-221
Circumferential PV ablation for chronic AFib
• Oral H et al. N Engl J Med (2006) 354: 934-941
RF Ablation vs Antiarrhythmic Drugs as
First-line Therapy
• Patients randomised to receive ablation (n=33) or
AADs (n=37): AFib-free Survival
AFib.free survival
1.0
0.8
0.6
0.4
PVI Group
Antiarrhythmic Drug
Group
0.2
0
0
100
200
300
Follow-up (days)
Wazni OM, et al. JAMA (2005) 293: 2634
Catheter Ablation vs. AADs Alone in
Drug-refractory AFib
AADs plus ablation (n=68) or AADs alone (n=69):
1 year follow-up
Ablation Group
Medical Group
AFib-free survival (%)
100
80
60
40
20
0
0
1
2
3
4
5
6
7
8
9
10
11
12
Months
Stabile G, et al. Eur Heart J (2006) 27: 216
Randomized Controlled Trial of Amiodarone +
Cardioversion + Catheter Ablation
Amiodarone & cardioversion (n=69) vs. amiodarone &
cardioversion plus PV ablation (n=77)
100
Circumferential
pulmonary-vein ablation
Control
Sinus rhythm (%)
80
60
40
20
0
1
2
3
4
5
6
7
8
9
10
11
12
Months
Oral H, et al. N Engl J Med (2006) 354: 9
Catheter Ablation is Successful
in the Long Term
No ERAF
ERAF
Freedom from Recurrent AFib
1.0
0.8
0.6
0.4
0.2
0
0
2
4
6
8
10
12
Months after PV isolation
Oral H, et al. J Am Coll Cardiol (2002) 40: 100
Complications Reported by Leading
Centres
Major complications with pulmonary vein ablation
in 1039 patients (6 series)
Events
(n)
Rate
(%)
Range in studies
(%)
Transient ischaemic attack
4
0.4
0-3
Permanent stroke
1
0.1
0-1
Severe PV stenosis
(>70%, symptomatic)
3
0.3
0-3
13
1.3
0-5
Tamponade / perforation
5
0.5
0-3
Severe vascular access
complication
3
0.3
0-4
Complication
Moderate PV stenosis
(40-70%, asymptomatic)
Verma A & Natale A Circulation (2005) 112: 1214
Cost Effectiveness
Analyses of Catheter
Ablation
Catheter Ablation May Be More Costeffective than Pharmacological Therapy
After 5 years, the cost of RF ablation was below that of medical
management and further diverged thereafter
118 patients with symptomatic,
drug-refractory AFib
1.52 ± 0.71 ablation procedures
32 weeks
Pharmacological treatment
Catheter ablation
€1590/year
€4715 followed by
€445/year
Weerasooriya R, et al. Pacing Clin Electrophysiol (2003) 26: 292
Differences in Hospital Visits and Costs
with and without Catheter Ablation
Although the initial cost of ablation is high, after ablation,
utilization of healthcare resources is significantly reduced
No ablation
Catheter ablation
Clinical visits per year
7.4 (2.5)
1.1 (0.6)
Emergency room visits per year
1.7 (0.9)
0.03 (0.17)
Hospitalization days per year
1.6 (0.8)
0 (0)
$1920 (889)
$87 (68)
Healthcare costs per year
Goldberg A, et al. J Interv Card Electrophysiol (2003) 8: 59
Catheter Ablation Cost-Effective in
Patients at High Risk of Stroke
Model to compare the cost-effectiveness of left
atrial catheter ablation (LACA), amiodarone, and
rate control therapy in the management of AFib
The use of LACA may be cost-effective in patients
with AFib at moderate risk for stroke
This model did not find it to be cost-effective in
low-risk patients.
Conclusions
Cost-effective in patients at moderate or
high risk of stroke
Chan DP, et al. J Am Coll Cardiol (2006) 47: 2513
Current Guidelines and
Summary
Current ACC/AHA/ESC Guidelines
Recurrent
Paroxysmal AF
Minimal or
no symptoms
Disabling symptoms
in AF
Anticoagulation and rate
control as needed
Anticoagulation and rate
control as needed
No drug for prevention
of AF
AAD therapy
AF ablation if AAD
treatment fails
ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation
J Am Coll Cardiol (2006) 48: 854
Recent Commentary
Why Ablation for AFib might be Considered FirstLine Therapy for Some Patients
“Current therapies, especially AAM, not only
are ineffective but also pose a threat to patient
QoL and even longevity.
In the hands of experienced operators, AF ablation is
an effective, safe, and established treatment for AF
that offers an excellent chance for a lasting cure …
unlike other therapies, ablation tackles AF at its
electrophysiological origin.”
Verma A & Natale A Circulation (2005) 112: 1214
Summary of catheter ablation (I)
• Catheter ablation for AFib has undergone significant
methodological and technical revolution since its
initial appearance two decades ago
• Discovery that PVs are a major source of ectopic
triggers was pivotal in determining efficacy of
procedure
• Significant technological advances in catheters and
imaging are further improving the efficiency of
catheter ablation
• 3D reconstructions of actual left atrial PV anatomy
using CT, MRI, or intracardiac echography enables
ever more accurate placement of lesions
Summary of catheter ablation
• High success rate
• Improves survival, cardiac function and freedom from
recurrence
• New data from RCTs confirm benefits
• Safe, with a risk comparable to other low-risk, routine
interventions
• Cost effective compared to standard pharmacological
therapy, at least in patients at moderate
thromboembolic risk